Luckily for David Cameron, a new Nespresso machine had been installed in the UK delegation office at the European Council building just before his first all-night EU session since becoming Prime Minister.

The machine also worked overtime. As dawn broke in Brussels yesterday, the only coffee left was decaffeinated. Some 120 shots of the real thing had been used up by Mr Cameron and his 20-odd team of officials.

Mr Cameron, who earlier joined EU leaders for a working dinner, snacked on apples, bananas and Haribo sweets during Thursday night. Between negotiating sessions, he worked on non-EU matters in his red box and signed letters. He grabbed 40 winks but only on a chair, not a sofa. “It has been a long couple of days,” a tired and red-faced Prime Minister said last night.

His hard day’s night was worth it. He could justifiably hail a significant victory in reining in EU spending, as he had promised. Although he claimed it was an example of how the UK can win friends and influence people, the real power-broker was Angela Merkel, the German Chancellor, without whom the row between “cutters” and “spenders” would probably not have been resolved.

Mr Cameron’s battle was just a warm-up for a much bigger war that he has already declared. He will find it much harder to win allies for Britain’s “new settlement” for he has pledged to put to the people in an in/out referendum by 2017. Mrs Merkel may be less willing than Mr Cameron hopes to go the extra mile to keep the UK in. Other budget allies like Sweden, the Netherlands and Denmark may take their cue from her.

The Prime Minister insisted that some EU countries welcomed the debate sparked by his big speech on Europe last month, recognising that he was calling for change in the EU as a whole, not just Britain’s relationship with it.

However, there were signs during the budget talks that Mr Cameron’s implicit threat to leave the EU could backfire. One negotiator remarked: “There is no question of accepting a budget dictated by a country when we don’t know whether it will be a member of the EU in 2017. There’s a revolt against Cameron.”

A French source acknowledged Mr Cameron’s “tenacity”, but his budget battle with François Hollande suggests the French President will owe him no favours.

The Prime Minister tried to build bridges by praising France’s intervention in Mali, but there is tension in the air. Mr Hollande offered only a perfunctory handshake when the two leaders met in the summit room.

Tory MPs will doubtless cheer Mr Cameron today and when he reports back to the Commons on Monday. But they are hard to please and may not be cheering for long.

His undoubted success in the budget talks will raise even greater expectations that he will be able to secure a significant return of powers from Brussels to London. The Prime Minister will struggle to fulfil them.

His MPs are a fickle bunch, as they showed by plotting to oust him as leader just days after he gave them the referendum they craved. As he tries to renegotiate Britain’s membership terms, Mr Cameron’s all-nighters in Brussels will be a lot harder – and more lonely – than his first one.