By Ian Dunt Follow @IanDunt
David Cameron has endured one of his toughest afternoons in the Commons, as MPs from across the political spectrum attacked his performance in Brussels.
The prime minister faced opposition from Labour frontbenchers, Tory backbenchers and members of his own Cabinet on a day that saw the goodwill he won after his late-night veto last year evaporate.
"With this prime minister a veto is not for life, it's just for Christmas," Ed Miliband told the chamber, to raucous laughter from the Labour benches.
"The phantom veto is now exposed. This agreement involves the European courts of justice, the European Commission, the buildings of the EU and 25 out of the 27 EU countries.
"It talks like a European treaty. It walks like a European treaty. It is a European treaty."
Mr Miliband, who was widely credited with one of his most confident and effective performances at the despatch box, continued: "For Britain he has secured absolutely no protections at all. Even his backbenchers say they can't believe a word he says.
"Britain stands with less influence than we have for a generation."
Mr Cameron, who looked deeply uncomfortable throughout the session, told Mr Miliband: "I'll deal with my backbenchers, you deal with yours."
Despite his best efforts, the benches behind the prime minister stayed sullen and silent through most of the session.
"We will watch this closely and if necessary we will take action, including legal action, if our national interests are threatened by the misuse of the institutions," Mr Cameron promised.
"This is a treaty outside the EU. We are not signing it. We did not ratify it and it places no obligation on the UK. There will be no inner group of EU countries distorting the single market via the treaty."
Tory backbencher Mark Reckless showed how dangerous events had become for the prime minister when he sarcastically asked: "Will the prime minister explain precisely what he's vetoed?"
Former foreign secretary Jack Straw said: "How can the prime minister possibly say that in substance this is not the same as a European treaty?"
Mr Cameron replied: "It's outside EU law because I made it outside EU law."
The stormy session capped off a difficult day for Mr Cameron, who admitted last night he would not prevent members of the new fiscal union from using institutions designed for the full EU.
He was also forced to accept that many aspects of the fiscal union were permissible under EU law, limiting Britain's ability to oppose them.
Two members of Cabinet – Iain Duncan Smith and Owen Paterson – reportedly spoke out against Mr Cameron during this morning's Cabinet meeting.
Mr Duncan Smith raised concerns about the use of EU institutions by the new 25-strong fiscal grouping, while Mr Paterson engaged in what was reported to be a more general debate on the eurozone.
It was difficult for Mr Duncan Smith to adopt a different approach after he offered categorical assurances on national television this weekend that the prime minister had vetoed the fiscal grouping from using EU institutions.
With an influential Cabinet secretary to lead the malcontents on the Tory backbenches, the eurosceptic wing of the party now presents a much more dangerous threat to the prime minister.
Tory backbencher Douglas Carswell said the veto had "fallen apart" and that last night's manoeuvres in Brussels were "final proof that we cannot trust politicians to make Europe policy".
Last year, 81 Tory backbenchers rebelled against the party whip on an EU vote, revealing the depth of potential opposition to events on the continent.