Conservative plans to enshrine an EU referendum in law have collapsed amid a bitter Coalition row.

The European Union (Referendum) Bill, which aimed at creating a legally binding obligation that the next government hold a vote on Britain's EU membership by 2017, cleared its first hurdle in Parliament earlier this month and was due to return to the Commons later in the current Parliamentary session.

But the Bill has now collapsed, with Conservatives accusing the Lib Dems of deliberately wrecking the legislation by demanding backing for reform of the so-called bedroom tax as their price for support.

Bob Neill, the backbench Tory MP who proposed the legislation, accused the Lib Dems of 'killing off' his Bill, saying: “They didn't have the guts to vote against an EU referendum in the House of Commons.

“Instead they have used Westminster tricks to try to deny the British people a say on their membership of the EU.”

He added: “This is will now be a major issue at the General Election. Two parties - Labour and Lib Dems - have done everything they can to stop a referendum.”

“Ukip aren't able to offer a referendum, and a vote for them makes the prospect of a Labour government led by Ed Miliband and Ed Balls, who don't want a referendum, more likely.

Bob Neill, Conservative backbencher Bob Neill, Conservative backbencher (Getty) “Only David Cameron and the Conservatives are offering a renegotiation followed by an in-out referendum by 2017.”

The Lib Dems, however, hit back with counter-claims that the Conservatives had deliberately sacrificed the Bill, and were now trying to make scapegoats of their junior Coalition partners.

A Lib Dem source said: “We can only assume they would prefer it hadn't become law by the time of the general election. They would prefer to try and deal with Ukip by saying the only way to get a referendum is to vote Tory. They couldn't do that if their Bill had become law.”

Lib Dem deputy leader Malcolm Bruce also accused the Conservatives of sacrificing the Bill to gain an electoral advantage over Ukip.

He said: “They clearly never wanted the referendum Bill to pass. The Liberal Democrats were never going to block their referendum Bill.

“We were happy to allow them to try and get it passed in the House of Commons. But the truth is they have folded like a cheap deck chair and are trying to make us take the blame by adding ridiculous conditions they knew we would not and could not accept.

“It is amazing that the Tories are prepared to sacrifice a bill they say they care about, for some short-term tactical distinction from Ukip.”

Talks have been held “at all levels” over recent days but came to a head on Tuesday.

Lib Dems wanted backing for a money resolution - a means of agreeing spending that is needed for Private Member's Bills to progress - in support of Andrew George's bid to reform the so-called bedroom tax.

Conservatives wanted backing for the same measure for Mr Neill's referendum Bill, and also the promise of Government time - a requirement Lib Dems said was inequitable.

A senior Liberal Democrat source said: “The Tories put forward a proposal they know for certain will be turned down by the Lib Dems - a completely unfair deal.

“They know we are not about to sign up to their Bill being given Government time when it is neither the Liberal Democrats position, nor the Coalition Government's, especially when they are not prepared to offer anything in return. The Coalition Government is a two-way street.

“The only logical conclusion that can be reached is that the Tories don't really want their Bill to pass and are trying to set the Lib Dems up as the scapegoats. Why else would they put forward a proposal they know cannot be agreed?”