Cameron mocks Labour 'confusion and weakness' over child benefit policy David Cameron speaks during prime minister's questions in the House of Commons. Photograph: PA David Cameron has mocked Ed Miliband for taking "policy-altering substances" after it was confirmed that a future Labour government would accept the coalition's decision to withdraw child benefit from higher rate taxpayers. As Labour unveils a major review this week of its spending and welfare policies, the prime minister joked that the party was carrying out so many U-turns it should hold its own grand prix. Speaking at his first session of prime minister's questions in six weeks, Cameron said: "I know that I've been the one on holiday in Ibiza but they have been the ones taking - how can I put it - policy-altering substances. Last week they were in favour of child benefit, now they are against child benefit. Then they were in favour of winter fuel allowance. Now they want to abolish winter fuel allowance. Only this morning we find out that they may not go ahead with this policy of scrapping child benefit. I think the truth is that the leader of the opposition is allowed to make coffee for the shadow chancellor but he can't tell him what the policy is. The prime minister turned on Labour after it was confirmed that the party would not reverse the coalition decision to withdraw child benefit from higher rate taxpayers. Ed Balls, the shadow chancellor, who announced on Monday that Labour would accept the current spending plans for 2015-16 as the basis for his plans, has decided that Labour cannot afford the £2.3bn needed to reverse the child benefit decision. Miliband, who will outline plans to impose a new cap on welfare spending on Thursday, attempted to focus on the crisis in the provision of accident and emergency care. The Labour leader accused the government of piling the pressure on A&E departments after more than a quarter of NHS walk-in centres closed in the first two years of Cameron's premiership. The prime minister acknowledged that there had been problems, though he blamed this on the GPs' contract introduced by the last government. I accept in the first quarter of this year there were problems and we need to get to grips with them. One of the problems is the GPs' contract signed by the last Labour government that basically let GPs get out of out of hours. Miliband accused the prime minister of being complacent and out of touch on the NHS. The Labour leader said: "He may have had six weeks away but he has got no better at answering the question. I do have to say to the prime minister he has got to do better than this on the A&E crisis. But Cameron accused Labour of failing to match the coalition's pledge to ensure NHS spending rises in line with inflation over the course of this parliament. Labour MPs shouted this was untrue, prompting Cameron to say: "Oh it's not [true]? Oh, that's changed as well. Oh, we've got a new health policy. Honestly, there are so many U-turns they should be having a grand prix. The prime minister had earlier pointed out that in his first appearance in the Commons as Labour leader, Miliband had attacked him for withdrawing child benefit from higher rate taxpayers. Miliband said in 2010: "On child benefit, is it not time that the prime minister had the grown-up sense to admit that he has got it wrong and that he has made the wrong decision? He should tell middle-income families up and down Britain that he will think again. Cameron said on Wednesday: "The very first time he stood at that dispatch box, totally condemning and attacking in the strongest possible terms what now turns out to be Labour policy. What complete confusion and weakness from the leader of the opposition.