Labour leader Ed Miliband has claimed the Government is "falling apart" amid reports of splits in the Cabinet and senior ministers lining themselves up to replace David Cameron.
Speaking at Prime Minister's Questions in the House of Commons, Mr Miliband said members of the Cabinet had "lost confidence" in the austerity policies pursued by Mr Cameron and Chancellor George Osborne.
Following reports of a U-turn on minimum pricing for alcohol, the Labour leader quipped: "Could the Prime Minister tell us, is there anything he could organise in a brewery?"
But Mr Cameron accused the Labour leader of failing to address the issues of the economy and welfare reform, and accused him of allowing the union bosses who support his party financially to determine its policies.
The clash came after reports that Education Secretary Michael Gove admonished Home Secretary Theresa May at Tuesday's meeting of Conservative Cabinet members for allowing rumours to rise up about her leadership ambitions.
Mrs May fuelled rumours that she is positioning for a post-Cameron era over the weekend by delivering a speech that ranged far beyond her brief. She was not on the Government's frontbenches for PMQs, but standing with other MPs near the door to the Commons chamber.
Defence Secretary Philip Hammond has also gone public with his call for deeper cuts to welfare in the 2015-16 spending review, while Business Secretary Vince Cable has made the case for more capital investment, funded by borrowing.
After an assault on the Government for Cabinet splits over economic policy and alcohol pricing, Mr Miliband told the Commons: "A week out from the Budget, they have got an economic policy that's failing, a Prime Minister that makes it up as he goes along, a Government that is falling apart, and all the time, it's the country that is paying the price."
But Mr Cameron retorted that Mr Miliband had provided "not a single positive suggestion for how to get on top of the deficit that he left, not a single suggestion for how to deal with the massive welfare bills that he left, not a single suggestion for how to improve standards in our schools".
Listing fund-raising dinners which Mr Miliband has recently had with unions including the GMB, Usdaw, Aslef, TSSA and Ucatt, Mr Cameron said: "Dinosaur after dinosaur, dinner after dinner. They pay the money, they get the policies, but the country will end up paying the price."