Former UKIP AM Mark Reckless has left the Conservative group in the assembly, he has announced.
He said he has left the party group because the UK government “has broken its promise to deliver Brexit”. Mr Reckless had not been a member of the party.
It comes as speculation mounts a Brexit Party assembly group could be formed.
Tory group leader Paul Davies thanked him “for his valuable contribution” over the last two years.
Mr Davies said: “I appreciate there are strong views on Brexit but our commitment is clear – Wales and the rest of the United Kingdom must leave the European Union.”
A spokesman for the South Wales East independent AM, who was not conducting interviews on Tuesday, said he had left the Tory group on “good terms”.