Essex Ukip MP Douglas Carswell has "made some history because as a party of one he has managed to have a backbench rebellion", the Prime Minister has told MPs.
David Cameron joked it was "something to be admired" as Mr Carswell, who previously defected from the Tories to Ukip, sought to put the Prime Minister on the spot over the issue of Britain's EU membership.
Speaking during Prime Minister's Questions, Mr Carswell said: "At the time of the Bloomberg speech the Prime Minister promised that he would seek the repatriation of power from Brussels. Power he said must float back to the member states. Social and employment law he specifically promised would be returned to Britain. Why is he not even asking for this any more."
Mr Cameron replied:
Douglas Carswell shrugged off the quip though posting on Twitter that his party was being heard.