Ten EU countries have rallied behind David Cameron to limit any rise in next year's euro-budget to 2.9%.
A statement circulated by the Prime Minister at a summit in Brussels was signed by Germany, France, the Netherlands, Sweden, the Czech Republic, Denmark, Austria, Finland, Slovenia and Estonia.
The 11 have enough voting clout to form a "blocking minority" if the rest of the member states try to settle on a higher figure in forthcoming compromise talks with MEPs and the European Commission, both wanting a 5.9% rise.
The Cameron initiative came once the Prime Minister realised that his call for a spending freeze next year was a non-starter. He then launched what amounted to a petition in a bid to lock in sufficient allies in a pact against anything more than 2.9% - which in itself would add £435 million a year to the UK's EU budget payments.
The statement condemned the attempt to increase the budget by 5.9%, saying: "These proposals are especially unacceptable at a time when we are having to take difficult decisions at national level to control public expenditure.
"The Council (of EU finance ministers) has proposed an increase in the EU budget spending of 2.91% for 2011. We are clear that we cannot accept any more than this."
One European Commission official downplayed the move, pointing out that a larger majority of EU governments backed a 2.9% rise in July, when EU finance ministers adopted a position on their 5.9% proposal.
On that occasion Chancellor George Osborne called for a freeze, but was outvoted.
The official commented: "So what's new? All we've got is Mr Cameron giving up on a freeze and getting agreement from 10 others on 2.9% - fewer countries than backed 2.9% three months ago."
Earlier a Downing Street spokesman said: "In an ideal world, we would not be seeing a 2.9% budget rise. This is about Europe getting its house in order."