The inflation-busting rise in EU spending approved by MEPs yesterday is “completely unacceptable”, Downing Street said today.

The European Parliament backed a 6.8% rise in EU spending for 2013 and an overall increase of at least 5% in the EU's long-term 2014/20 budget, both of which are due to be agreed before the end of the year.

Last Friday, Prime Minister David Cameron threatened to veto any long-term EU spending increase above inflation - effectively a real-terms spending freeze for the EU budget.

The long-term budget for 2014/20 requires unanimity among the 27 member-states, giving the UK a veto when leaders of national governments gather for a special European Council summit next month. But the budget for the single year 2013 is decided by qualified majority voting, meaning Britain could be over-ruled.

Mr Cameron's official spokesman told a regular media briefing in Westminster today: "We think European budgets need to reflect the context, which is that countries across Europe are having to take some very tough decisions on public spending.

"I think we look at that proposal from the European Parliament and it is just completely unacceptable."

British Euro-MPs joined forces to fight the budget plans in yesterday's vote, but were outnumbered by five to one in a Strasbourg vote endorsing European Commission demands for more cash to fund EU policies. The proposal must be approved by the European Council before coming into effect.

The Council voted earlier this year for a 2.79% rise in the EU's £105 billion budget in 2013, but the UK and several other countries - including France, Germany, Sweden, Finland, Austria, Denmark and the Netherlands - opposed even this reduced increase.