diff --git a/.github/sync_labels.py b/.github/sync_labels.py
new file mode 100755
index 0000000000..f70bc58d45
--- /dev/null
+++ b/.github/sync_labels.py
@@ -0,0 +1,563 @@
+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+
+r"""
+Python script to sync labels that are migrated from Trac selection lists.
+"""
+
+##############################################################################
+#       Copyright (C) 2023 Sebastian Oehms <seb.oehms@gmail.com>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 2 of the License, or
+# (at your option) any later version.
+#                  http://www.gnu.org/licenses/
+##############################################################################
+
+import os
+import sys
+from logging import info, warning, getLogger, INFO
+from json import loads
+from enum import Enum
+
+class SelectionList(Enum):
+    """
+    Abstract Enum for selection lists.
+    """
+    def succ(self):
+        """
+        Return the successor of `self`.
+        """
+        l = list(self.__class__)
+        i = l.index(self) + 1
+        if i >= len(l):
+            return None
+        return l[i]
+
+class ReviewDecision(Enum):
+    """
+    Enum for `gh pr view` results for `reviewDecision`.
+    """
+    changes_requested = 'CHANGES_REQUESTED'
+    approved = 'APPROVED'
+    unclear = 'COMMENTED'
+
+class Priority(SelectionList):
+    """
+    Enum for priority lables.
+    """
+    blocker = 'p: blocker /1'
+    critical = 'p: critical /2'
+    major = 'p: major /3'
+    minor = 'p: minor /4'
+    trivial = 'p: trivial /5'
+
+class State(SelectionList):
+    """
+    Enum for state lables.
+    """
+    positive_review = 's: positive review'
+    needs_work = 's: needs work'
+    needs_review = 's: needs review'
+    needs_info = 's: needs info'
+
+
+def selection_list(label):
+    """
+    Return the selection list to which `label` belongs to.
+    """
+    for sel_list in [Priority, State]:
+        for item in sel_list:
+            if label == item.value:
+                return sel_list
+    return None
+
+class GhLabelSynchronizer:
+    """
+    Handler for access to GitHub issue via the `gh` in the bash command line
+    of the GitHub runner.
+    """
+    def __init__(self, url, actor):
+        """
+        Python constructor sets the issue / PR url and list of active labels.
+        """
+        self._url = url
+        self._actor = actor
+        self._labels = None
+        self._author = None
+        self._draft = None
+        self._open = None
+        self._review_decision = None
+        self._reviews = None
+        self._commits = None
+
+        number = os.path.basename(url)
+        self._pr = True
+        self._issue = 'pull request #%s' % number
+        if url.rfind('issue') != -1:
+            self._issue = 'issue #%s' % number
+            self._pr = False
+        info('Create label handler for %s and actor %s' % (self._issue, self._actor))
+
+    def is_pull_request(self):
+        """
+        Return if we are treating a pull request.
+        """
+        return self._pr
+
+    def view(self, key):
+        """
+        Return data obtained from `gh` command `view`.
+        """
+        issue = 'issue'
+        if self._pr:
+            issue = 'pr'
+        cmd = 'gh %s view %s --json %s' % (issue, self._url, key)
+        from subprocess import check_output
+        return loads(check_output(cmd, shell=True))[key]
+
+    def is_open(self):
+        """
+        Return if the issue res. PR is open.
+        """
+        if self._open is not None:
+            return self._open
+        if self.view('state') == 'OPEN':
+            self._open = True
+        else:
+            self._open = False
+        info('Issue %s is open %s' % (self._issue, self._open))
+        return self._open
+
+    def is_draft(self):
+        """
+        Return if the PR is a draft.
+        """
+        if self._draft is not None:
+            return self._draft
+        if self.is_pull_request():
+            self._draft = self.view('isDraft')
+        else:
+            self._draft = False
+        info('Issue %s is draft %s' % (self._issue, self._draft))
+        return self._draft
+
+    def get_labels(self):
+        """
+        Return the list of labels of the issue resp. PR.
+        """
+        if self._labels is not None:
+            return self._labels
+        data = self.view('labels')
+        self._labels = [l['name'] for l in data]
+        info('List of labels for %s: %s' % (self._issue, self._labels))
+        return self._labels
+
+    def get_author(self):
+        """
+        Return the author of the issue resp. PR.
+        """
+        if self._author is not None:
+            return self._author
+        data = self.view('author')
+        self._author = self.view('author')['login']
+        info('Author of %s: %s' % (self._issue, self._author))
+        return self._author
+
+    def get_review_decision(self):
+        """
+        Return the reviewDecision of the PR.
+        """
+        if not self.is_pull_request():
+            return None
+
+        if self._review_decision is not None:
+            return self._review_decision
+
+        data = self.view('reviewDecision')
+        if data:
+            self._review_decision = ReviewDecision(data)
+        else:
+            self._review_decision = ReviewDecision.unclear
+        info('Review decision for %s: %s' % (self._issue, self._review_decision.value))
+        return self._review_decision
+
+    def get_reviews(self):
+        """
+        Return the list of reviews of the PR.
+        """
+        if not self.is_pull_request():
+            return None
+
+        if self._reviews is not None:
+            return self._reviews
+
+        self._reviews = self.view('reviews')
+        info('Reviews for %s: %s' % (self._issue, self._reviews))
+        return self._reviews
+
+    def get_commits(self):
+        """
+        Return the list of commits of the PR.
+        """
+        if not self.is_pull_request():
+            return None
+
+        if self._commits is not None:
+            return self._commits
+
+        self._commits = self.view('commits')
+        info('Commits for %s: %s' % (self._issue, self._commits))
+        return self._commits
+
+    def gh_cmd(self, cmd, arg, option):
+        """
+        Perform a system call to `gh` for `cmd` to an isuue resp. PR.
+        """
+        issue = 'issue'
+        if self._pr:
+            issue = 'pr'
+        cmd_str = 'gh %s %s %s %s "%s"' % (issue, cmd, self._url, option, arg)
+        os.system(cmd_str)
+
+    def edit(self, arg, option):
+        """
+        Perform a system call to `gh` to edit an issue resp. PR.
+        """
+        self.gh_cmd('edit', arg, option)
+
+    def review(self, arg, text):
+        """
+        Perform a system call to `gh` to review a PR.
+        """
+        self.gh_cmd('review', arg, '-b %s' % text)
+
+    def active_partners(self, item):
+        """
+        Return the list of other labels from the selection list
+        of the given one that are already present on the issue / PR.
+        """
+        sel_list = type(item)
+        partners = [i for i in sel_list if i != item and i.value in self.get_labels()]
+        info('Active partners of  %s: %s' % (item, partners))
+        return partners
+
+    def needs_work(self, only_actor=True):
+        """
+        Return `True` if the PR needs work. This is the case if
+        the review decision requests changes or if there is any
+        review reqesting changes.
+        """
+        ch_req = ReviewDecision.changes_requested
+        rev_dec =  self.get_review_decision()
+        if rev_dec:
+            if rev_dec == ch_req:
+               info('PR %s needs work (by decision)' % self._issue)
+               return True
+            else:
+               info('PR %s doesn\'t need work (by decision)' % self._issue)
+               return False
+
+        revs = self.get_reviews()
+        if only_actor:
+            revs = [rev for rev in revs if rev['author']['login'] == self._actor]
+        if any(rev['state'] == ch_req.value for rev in revs):
+            info('PR %s needs work' % self._issue)
+            return True
+        info('PR %s doesn\'t need work' % self._issue)
+        return False
+
+    def positive_review(self, only_actor=True):
+        """
+        Return `True` if the PR has positive review. This is the
+        case if the review decision is approved or if there is any
+        approved review but no changes requesting one.
+        """
+        appr = ReviewDecision.approved
+        rev_dec =  self.get_review_decision()
+        if rev_dec:
+            if rev_dec == appr:
+                info('PR %s has positve review (by decision)' % self._issue)
+                return True
+            else:
+                info('PR %s doesn\'t have positve review (by decision)' % self._issue)
+                return False
+
+        if self.needs_work():
+            info('PR %s doesn\'t have positve review (needs work)' % self._issue)
+            return False
+
+        revs = self.get_reviews()
+        if only_actor:
+            revs = [rev for rev in revs if rev['author']['login'] == self._actor]
+            if any(rev['state'] == appr.value for rev in revs):
+                info('PR %s has positve review (by decision)' % self._issue)
+                return True
+        info('PR %s doesn\'t have positve review (needs work)' % self._issue)
+        return False
+
+    def approve_allowed(self):
+        """
+        Return if the actor has permission to approve this PR.
+        """
+        author = self.get_author()
+        revs = self.get_reviews()
+        if not any(rev['author']['authorAssociation'] == 'MEMBER' for rev in revs):
+            info('PR %s can\'t be approved because of missing member review' % (self._issue))
+            return False
+
+        revs = [rev for rev in revs if rev['author']['login'] != self._actor]
+        ch_req = ReviewDecision.changes_requested
+        if any(rev['state'] == ch_req.value for rev in revs):
+            info('PR %s can\'t be approved by %s since others reqest changes' % (self._issue, self._actor))
+            return False
+
+        if author != self._actor:
+            info('PR %s can be approved by %s' % (self._issue, self._actor))
+            return True
+
+        revs = [rev for rev in revs if rev['author']['login'] != 'github-actions']
+        if not revs:
+            info('PR %s can\'t be approved by the author %s since no other person reviewed it' % (self._issue, self._actor))
+            return False
+
+        comts = self.get_commits()
+        authors = sum(com['authors'] for com in comts)
+        authors = [auth for auth in authors if not auth['login'] in (self._actor, 'github-actions')]
+        if not authors:
+            info('PR %s can\'t be approved by the author %s since no other person commited to it' % (self._issue, self._actor))
+            return False
+
+        info('PR %s can be approved by the author %s as co-author' % (self._issue, self._actor))
+        return True
+
+    def approve(self):
+        """
+        Approve the PR by the actor.
+        """
+        self.review('--approve', '%s approved this PR' % self._actor)
+        info('PR %s approved by %s' % (self._issue, self._actor))
+
+    def request_changes(self):
+        """
+        Request changes for this PR by the actor.
+        """
+        self.review('--request-changes', '%s requested changes for this PR' % self._actor)
+        info('Changes requested for PR %s by %s' % (self._issue, self._actor))
+
+    def add_comment(self, text):
+        """
+        Perform a system call to `gh` to add a comment to an issue or PR.
+        """
+
+        self.gh_cmd('comment', text, '-b')
+        info('Add comment to %s: %s' % (self._issue, text))
+
+    def add_label(self, label):
+        """
+        Add the given label to the issue or PR.
+        """
+        if not label in self.get_labels():
+            self.edit(label, '--add-label')
+            info('Add label to %s: %s' % (self._issue, label))
+
+    def add_default_label(self, item):
+        """
+        Add the given label if there is no active partner.
+        """
+        if not self.active_partners(item):
+            self.add_label(item.value)
+
+    def on_label_add(self, label):
+        """
+        Check if the given label belongs to a selection list. If so, remove
+        all other labels of that list. In case of a state label reviews are
+        booked accordingly.
+        """
+        sel_list = selection_list(label)
+        if not sel_list:
+            return
+
+        item = sel_list(label)
+        if label not in self.get_labels():
+            # this is possible if two labels of the same selection list
+            # have been added in one step (via multiple selection in the
+            # pull down menue). In this case `label` has been removed
+            # on the `on_label_add` of the first of the two labels
+            partn = self.active_partners(item)
+            if partn:
+                self.add_comment('Label *%s* can not be added due to *%s*!' % (label, partn[0].value))
+            else:
+                warning('Label %s of %s not found!' % (label, self._issue))
+            return
+
+        if sel_list is State:
+            if not self.is_pull_request():
+                if item != State.needs_info:
+                    self.add_comment('Label *%s* can not be added to an issue. Please use it on the corresponding PR' % label)
+                    self.remove_label(label)
+                    return
+
+            if item == State.positive_review:
+                if self.approve_allowed():
+                    self.approve()
+                elif self.needs_work():
+                    # PR still needs work
+                    self.add_comment('Label *%s* can not be added. Please use the corresponding functionality of GitHub' % label)
+                    self.select_label(State.needs_work)
+                    return
+                else:
+                    # PR still needs review
+                    self.add_comment('Label *%s* can not be added. Please use the corresponding functionality of GitHub' % label)
+                    if self.is_draft():
+                        self.remove_label(label)
+                    else:
+                        self.select_label(State.needs_review)
+                    return
+
+            if item == State.needs_work:
+                self.request_changes()
+                if not self.needs_work():
+                    # change request of actor could not be set
+                    self.add_comment('Label *%s* can not be added. Please use the corresponding functionality of GitHub' % label)
+                    if self.is_draft():
+                        self.remove_label(label)
+                    else:
+                        self.select_label(State.needs_review)
+                    return
+
+        for other in sel_list:
+            if other != item:
+                self.remove_label(other.value)
+
+    def select_label(self, item):
+        """
+        Add the given label and remove all others.
+        """
+        self.add_label(item.value)
+        sel_list = type(item)
+        for other in sel_list:
+            if other != item:
+                self.remove_label(other.value)
+
+    def remove_label(self, label):
+        """
+        Remove the given label from the issue or PR of the handler.
+        """
+        if label in self.get_labels():
+            self.edit(label, '--remove-label')
+            info('Remove label from %s: %s' % (self._issue, label))
+
+    def on_label_remove(self, label):
+        """
+        Check if the given label belongs to a selection list. If so, the
+        successor of the label is added except there is none or there
+        exists another label of the corresponding list. In case of a
+        state label reviews are booked accordingly.
+        """
+        sel_list = selection_list(label)
+        if not sel_list:
+            return
+
+        item = sel_list(label)
+        if label in self.get_labels():
+            # this is possible if two labels of the same selection list
+            # have been removed in one step (via multiple selection in the
+            # pull down menue). In this case `label` has been added
+            # on the `on_label_remove` of the first of the two labels.
+            partn = self.active_partners(item)
+            if partn:
+                self.on_label_add(partn[0].value)
+            return
+
+        if sel_list is State:
+            if not self.is_pull_request():
+                return
+            if item == State.positive_review:
+                if self.positive_review():
+                    self.request_changes()
+                    self.select_label(State.needs_work)
+                elif self.positive_review(only_actor=False):
+                    self.add_comment('Label *%s* can not be removed. Please use the corresponding functionality of GitHub' % label)
+                    self.select_label(item)
+                elif not self.is_draft():
+                    self.select_label(State.needs_review)
+                return
+            elif item == State.needs_work:
+                if self.needs_work(only_actor=False):
+                    self.add_comment('Label *%s* can not be removed. Please use the corresponding functionality of GitHub' % label)
+                    self.select_label(item)
+                elif not self.is_draft():
+                    self.select_label(State.needs_review)
+                return
+
+        if not self.active_partners(item):
+            # if there is no other in the same selection list
+            # add the next weaker label if it exists
+            succ = sel_list(label).succ()
+            if succ:
+                self.select_label(succ)
+            
+    def on_converted_to_draft(self):
+        """
+        Remove all state labels.
+        """
+        for item in State:
+            self.remove_label(item.value)
+
+
+###############################################################################
+# Main
+###############################################################################
+cmdline_args = sys.argv[1:]
+
+getLogger().setLevel(INFO)
+info('cmdline_args (%s) %s' % (len(cmdline_args), cmdline_args))
+
+if len(cmdline_args) < 4:
+    print('Need 5 arguments: action, url, actor, label, rev_state' )
+    exit
+else:
+    action, url, actor, label, rev_state = cmdline_args
+
+info('action: %s' % action)
+info('url: %s' % url)
+info('label: %s' % label)
+info('actor: %s' % actor)
+info('rev_state: %s' % rev_state)
+
+gh = GhLabelSynchronizer(url, actor)
+
+if action in ('opened', 'reopened'):
+    if gh.is_pull_request():
+        if not gh.is_draft():
+            gh.add_default_label(State.needs_review)
+
+if action in ('closed', 'reopened'):
+    for lab in State:
+        gh.remove_label(lab.value)
+
+if action == 'labeled':
+    gh.on_label_add(label)
+
+if action == 'unlabeled':
+    gh.on_label_remove(label)
+
+if action == 'ready_for_review':
+    gh.select_label(State.needs_review)
+
+if action == 'converted_to_draft':
+    gh.on_converted_to_draft()
+
+if action == 'submitted':
+    if rev_state == 'approved':
+        if gh.positive_review():
+            gh.select_label(State.positive_review)
+
+    if rev_state == 'changes_requested':
+        if gh.needs_work():
+            gh.select_label(State.needs_work)
+
+if action in ('review_requested', 'ready_for_review'):
+    gh.select_label(State.needs_review)
diff --git a/.github/workflows/sync_labels.yml b/.github/workflows/sync_labels.yml
new file mode 100644
index 0000000000..4e11a94277
--- /dev/null
+++ b/.github/workflows/sync_labels.yml
@@ -0,0 +1,42 @@
+# This workflow synchronizes groups of labels that correspond
+# to items of selection list in Trac. It controls that in each
+# such case there is just one label of the list present.
+# Furthermore in the case of the state it checks the labels
+# to coincide with the corresponding review state.
+
+name: Synchronize selection list lables
+
+on:
+  pull_request_review:
+    types: [submitted]
+  issues:
+    types: [opened, reopened, closed, labeled, unlabeled]
+  pull_request:
+    types: [opened, reopened, closed, ready_for_review, converted_to_draft, labeled, unlabeled]
+  pull_request_target:
+    types: [opened, reopened, closed, ready_for_review, converted_to_draft, labeled, unlabeled]
+
+jobs:
+  synchronize:
+    runs-on: ubuntu-latest
+    steps:
+      # Download the Python script
+      - name: Download script
+        id: download
+        run: |
+          curl -L -O "https://raw.githubusercontent.com/"$REPO"/master/.github/sync_labels.py"
+          chmod a+x sync_labels.py
+        env:
+          REPO: ${{ github.repository }}
+
+      # Perform synchronization
+      - name: Call script
+        run: ./sync_labels.py $ACTION $ISSUE_URL $PR_URL $ACTOR "$LABEL" "$REV_STATE"
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          ACTION: ${{ github.event.action }}
+          ISSUE_URL: ${{ github.event.issue.html_url }}
+          PR_URL: ${{ github.event.pull_request.html_url }}
+          ACTOR: ${{ github.actor }}
+          LABEL: ${{ github.event.label.name }}
+          REV_STATE: ${{ github.event.review.state }}