05/06/2013 09:04 BST | Updated 05/06/2013 09:10 BST

PMQs: David Cameron Accuses Ed Miliband Of Taking 'Policy-Altering Substances' (VIDEO)

David Cameron accused Ed Miliband of taking "policy-altering substances" at prime minister's questions on Wednesday afternoon, following reports the Labour Party will ditch its opposition to cuts to child benefit.

Labour MPs cheered loudly as the prime minister stood up to speak, mocking him for having only been present at three PMQs in the last eight weeks. However Cameron, fresh from his holiday in Ibiza, was raring to go.

"The very first time the leader of the Opposition came to that Despatch Box he attacked me for taking child benefit away from higher earners and yet today we learn it is now Labour's official policy to take child benefit away from higher earners. Total and utter confusion," he said. "Perhaps he can explain himself when he gets to his feet?"

Miliband, who wanted to focus on the pressure A&E services are suffering, did not rise to the challenge.

And only four minutes in to the session Cameron had already targeted the apparent Labour policy U-turn three times. "Not one word what he said two years ago totally condemning and attacking in the strongest terms what now turns out to be Labour policy," he said. "What complete confusion and weakness from the leader of the Opposition."

Cameron then added to the amusement of George Osborne and Nick Clegg: "I know I've been the one on holiday in Ibiza but they've [Labour] been the ones taking policy-altering substances."

On Thursday Miliband is expected to say he would not reverse the coalition's cuts to child benefit for the better off and that he supports a benefit cap.

The party leader is due to use a speech tomorrow to acknowledge a Labour government would not be able to afford the £2.3bn to reinstate the payments, despite having opposed the cuts at the time.

The move comes after shadow chancellor Ed Balls announced on Monday that Labour would end winter fuel payments for better off pensioners and will be seen as a further attempt by the party to rebuild its economic credibility.

However Labour had previously strongly criticised Chancellor George Osborne's decision to cut child benefit for higher rate taxpayers, arguing it was unfair and showed ministers were out of touch with hard-working families.