Conservatives stand ready to "foil" the Liberal Democrats over the EU referendum bill, the backbencher championing the legislation has said.
Tory MP Bob Neill, who came third in the private members' ballot, is reintroducing the EU referendum bill piloted by James Wharton and Lord Dobbs through parliament in the last session.
The legislation seeks to guarantee in law that an in-out referendum will take place in 2017. David Cameron has pledged to hold such a vote if he is prime minister but Tory MPs want the poll guaranteed in law before next year's general election.
As reported by Politics.co.uk, the Conservatives now stand ready to use the Parliament Act to force the bill through. Neill has until three weeks before the end of the parliamentary session to get the bill through the Commons, after which it will automatically become law.
"Labour and Lib Dems won't be able to kill it in the Lords," Neill wrote in an article for the Express.
"The Parliament Act means it need not go there again. If they want to stop the British people having their say in a referendum in 2017 they'll have to block it in the House of Commons, in full public view.
"My colleagues led by the prime minister will do everything we can to foil Liberal and Labour schemes and ensure the people get their say."
Both sides accept there are procedural opportunities to derail the process, but Tory eurosceptics hope the bill will at the very least highlight Ed Miliband's reluctance to accept the need for an automatic referendum.
"It is now up to Labour and the Lib Dems to decide whose side they're on," Neill added.
"That of the 'we know best' European political elite. Or standing with the Conservatives on the side of the people. Their actions as this bill progresses in the next few months will show where their loyalties lie."
Meanwhile the Unite union, one of Labour's biggest financial backers, is reportedly calling on Miliband to endorse Cameron's proposals to put the issue to a vote.
A vote at its annual conference on Wednesday will suggest the party has been too "uncritical" of the EU while itself backing Britain's continued membership, the Financial Times reported.