A senior Liberal Democrat source has said the party was "nonplussed" about the Prime Minister's move and the issue of legislation on a referendum was not discussed during negotiations on the Queen's Speech:
The Conservatives are free to bang on about Europe as much as they like within their own party.
Rather than spend time debating an internal Tory trauma on an issue where the Government has a clear position, the Liberal Democrats will focus on jobs and growth.
The Coalition Government have already passed a law – fully supported by the Liberal Democrats – that guarantees a referendum next time there is a transfer of power from Westminster to Brussels.
When we were discussing that legislation, we didn’t hear a peep out of the Conservatives about all this. Neither did we in discussions on the Queen’s Speech.
We’re a bit non-plussed that the Conservatives keep moving the goalposts.
Cameron has pledged to back a Conservative MP's EU referendum bill, as Cable labelled the move potentially 'damaging' for the country.
114 Conservative backbenchers have voted in favour of a eurosceptic motion to amend the Queen's Speech in defiance of the Prime Minister.
David Cameron has denied he has buckled under pressure from his backbench MPs over the EU debate.