Prime Minister David Cameron has warned EU leaders to stop "tinkering" with Europe's budget and make real savings in line with national austerity efforts.

Arriving at the Brussels summit for a second day of negotiations on Europe's spending priorities for 2014-2020, he said Thursday's meeting had done nothing to tackle "unaffordable" spending programmes.

"I don't think there's been enough progress so far," he said. "There really is a problem that there hasn't been the progress in cutting back proposals for additional spending.

"It isn't the time for tinkering. It isn't the time for moving money from one part of the budget to another. We need unaffordable spending cut. That's what's happening at home and that's what needs to happen here."

German chancellor Angela Merkel and French president Francois Hollande both played down the chances of a final deal this weekend after studying a new compromise plan presented late on Thursday night by summit chairman Herman Van Rompuy.

It retained the same overall budget figure on offer when the talks began - 940 billion euro (£756 billion) - but with a redistribution of funds between various policy areas in a bid to appease those calling for increases and those demanding restraint.

Mr Cameron's remarks on the way into more talks on Friday reflected frustration that his calls for an overall reduction and for cuts in Eurocrats' pay and benefits - in solidarity with "ordinary" public sector workers - seemed to have been ignored.

A potential threat to the UK's rebate on its EU bills still remains. Richard Corbett, an adviser to Mr Van Rompuy, insisted that nobody was suggesting changing the rebate mechanism which reduces the UK contribution to Brussels by nearly £3 billion a year, but budget adjustments being demanded elsewhere could affect the actual sum.

That would be firmly rejected by Mr Cameron - just as Mr Hollande is resisting efforts to trim the size of the EU agriculture budget and more than a dozen relatively poor central European member states are insisting on keeping the scale of cash benefits they get from "cohesion" funds.

Mr Van Rompuy is holding a second series of individual talks with some leaders in a bid to redraw the budget puzzle, before the full summit convenes.