Only the Conservatives can be trusted with the NHS, David Cameron has said, in a sign of increasingly tense relations with his Liberal Democrat coalition partners.
The embarrassing gaffe comes in a week which has seen Lib Dems and Conservatives increasingly at odds over the government's health and social care bill.
The prime minister was forced on to the defensive over the coalition's proposals for NHS reform in this week's prime minister's questions.
Pressed by Labour leader Ed Miliband on the issue for all of the opposition's six questions, Mr Cameron repeated previous promises that there would be "significant and substantial changes to the reforms".
That claim was rejected by Mr Miliband, who suggested the 'pause' in the health and social care bill's progress through parliament was "nothing more than a sham".
Mr Cameron asked Mr Miliband to correct his claim that waiting times had risen "month on month in this government".
Mr Miliband declined to do so, instead focusing on criticisms of the reform proposals.
"Doesn't his mess on the NHS tell us all we need to know about this prime minister?" he said.
"He breaks his promises, he doesn't think things through and when the going gets tough he dumps on his colleagues."
Mr Cameron replied: "There's only one party you can trust on the NHS, and it's the one that I lead."
That remark appeared to prompt some discomfort from Nick Clegg, the leader of the Liberal Democrats who was sitting to Mr Cameron's right-hand side.
"He should be seriously engaging in how we make sure we have a strong NHS for all our people for the future," Mr Cameron continued.
"Instead we have empty opposition which got him absolutely nowhere last week."
The prime minister had livened up the last two PMQs sessions by making bizarre cultural references to Michael Winner and Benny Hill.
His contribution this week appeared more pre-prepared. He said: "I have to admit some of the recent cultural references I've made have been a bit out of date. But I have to say when I look at the honourable gentleman who told us the fightback would start in Scotland rather reminds me of Eddie the Eagle."