The government of Prime Minister David Cameron has been plunged into crisis after a rebellion Wednesday evening of more than 100 Conservative Members of Parliament. The rebels from the Tory “euro-sceptic” wing are demanding the adoption of immediate legislation on an in-out referendum on Britain’s membership of the European Union (EU).

Including ministerial aides, 116 Conservatives, half of the party’s MPs, voted against the government. They forced through the vote in response to the Queen’s Speech last week, outlining the government’s legislative programme for the upcoming year.

Traditionally, a vote is held in parliament welcoming the Queen’s Speech. An amendment put forward by Tory John Barron, however, expressed “regret” that the speech omitted reference to holding a referendum on EU membership before the general election due in 2015.

This is the first time since 1946 that members of a governing party have voted against a Queen’s Speech. The rebellion was on a substantially larger scale than that of October 2011 when 81 Tory MPs voted for a referendum.

MPs from other parties also supported the amendment, including 11 from Labour, four from Northern Ireland’s Democratic Unionists, John Hemming from the Liberal Democrats and the former Labour and now Respect MP George Galloway.

Cameron had pledged that if re-elected in 2015 as a majority party, he would hold a referendum by 2017, following a renegotiation of Britain’s membership terms—a position not supported by the Tory’s coalition partners, the Liberal Democrats.

Although the euro-sceptic amendment was defeated by 277 votes to 131 due to opposition from Labour and the Liberal Democrats, the size of the backbench rebellion is a severe blow to Cameron’s leadership and has broad ramifications for the entire political system.

The demand for a referendum on EU membership is always cast by the media as an attempt to honour the will of the electorate. This is nonsense. The row within Britain’s elite has nothing to do with popular opposition to the EU’s imposition of austerity measures and the anti-democratic manner in which those are being driven through. All sides in the debate fully support draconian austerity.

Cameron’s position, supported by important sections of business and finance, is that the threat of a referendum should be used to pressure other EU powers to refashion the trade bloc in Britain’s interests. This centres on greater “liberalisation” of the European market, as well as pressing Germany in particular to come up with more funds to bail out British and American banking interests.

The euro-sceptics argue this perspective is unrealisable. Under conditions of deepening crisis in Europe, which threatens the collapse of the eurozone in its existing form, the path is being cleared for a “two-tier” Europe that would threaten the interests of British capital. Much of the ire of the “sceptics” is directed against European Union proposals for a financial transaction tax that would hit the profits of the City of London.

Every wing of the British political establishment agrees that the drive for greater “competitiveness” must be at the expense of the jobs, wages and living standards of the working class.

In his Daily Telegraph column, Boris Johnson, the Conservative mayor of London and a prominent euro-sceptic, claimed that Britain’s economic problems were the result of a workforce that suffers from “sloth”. “Why are we still, person for person, so much less productive than the Germans?” he asked. “That is now a question more than a century old, and the answer has nothing to do with the EU. In or out of the EU, we must have a clear vision of how we are going to be competitive in a global economy”.

Cameron has repeatedly tried to appease his euro-sceptic opponents with concessions, only to succeed in emboldening them further. Just 24 hours prior to the vote he took the unprecedented step of rushing out a draft bill for an in-out referendum by 2017. Then he allowed Tory MPs a free vote on the amendment.

With his cabinet divided, however, Cameron had instructed ministers to abstain to stem the size of the rebellion. Nonetheless, in the run-up to the vote, Education Secretary Michael Gove and Defence Secretary Philip Hammond made public statements indicating they would support Britain leaving the EU if a referendum were to be held now. Reportedly, seven other ministers are also prepared to vote to leave the EU.

The situation has provoked nervousness in powerful circles. The Financial Times berated Cameron for his “willingness to defer to his own right flank”. Stating that “a strain of collective madness has descended over the Conservative party in recent days”, it questioned Cameron’s leadership abilities.

Columnist Janan Ganesh said of the rebels, “no concession satisfies those who ultimately want to leave the EU, even if they say it will before receiving it”, and concluded, “They may have crossed into outright ungovernability”.

These events have served to make clearer the role of the anti-EU United Kingdom Independence Party (UKIP) as a mechanism for engineering a political shift even further to the right. UKIP recently won an average of 25 percent in the local elections wards where it stood, winning support mainly from discontented Tory voters. It has garnered support from a number of Conservative backbenchers, including Simon Bone and Nadine Dorries.

This week Dorries—after only recently being admitted back into the party—wrote in the Spectator magazine that she is considering standing as a joint Conservative-UKIP candidate at the next general election. Another Tory, Jacob Rees-Mogg, suggested the two parties could merge—with UKIP leader Nigel Farage replacing Liberal Democrat Nick Clegg as deputy prime minister. Farage has said UKIP would form an electoral pact with the Conservatives, providing Cameron is removed as leader.

The conflict deepened this week, with the announcement that euro-sceptic Tory MP James Wharton will organise efforts to force a bill on an EU referendum onto the statute book that would split the government coalition.

The implications of these divisions go well beyond Britain. While the vote was taking place, Cameron was in the United States for talks with President Barack Obama, including on proposals for a EU-US free trade deal, the Transatlantic Trade and Investment Partnership. Cameron told the Wall Street Journal that a proposed EU-US free trade area “could add as much as £10 billion to the British economy and £63 billion ($97 billion) to US GDP”.

A central component of the “special [US-UK] relationship” is Britain’s role as a supporter of American interests in Europe. In a press conference with Cameron Monday, Obama reiterated his opposition to Britain’s withdrawing from the EU. Speaking of the growing rift in the Tory party, he said of the UK relationship with the EU, “You probably want to see if you can fix what’s broken in a very important relationship before you break it off”.

“I think the UK’s participation in the EU is an expression of its influence and its role in the world, as well as, obviously, a very important economic partnership”, he continued.

Cameron’s plight has also caused alarm in Berlin. Leading figures in Chancellor Angela Merkel’s government have described a UK exit from the EU as a “disaster” and have said they are willing to look at renegotiating its membership terms to stave off such an event.

According to the Guardian, Berlin regards the UK as critical in countering “protectionist pressures in France and other Mediterranean countries” and as a key ally in forcing through “structural economic reforms” to restore European competitiveness. Any concession to Britain on revising existing treaties, however, opens up the prospect of referendums being held (and lost) in other EU member states—most notably France—that would further destabilise the eurozone.