The Tory MP Nadine Dorries has said she is considering running on a joint Conservative-UKIP ticket in the next election as a way of helping the "right unite".
A Conservative party spokesman clarified soon after that this was "not going to happen".
Dorries told BBC News that she was looking at the possibility of seeking an "endorsement" from UKIP because the two parties "have some synergy" on issues like Europe and gay marriage.
"It's not [about] being adopted by UKIP. It's just seeking UKIP endorsement so that they don't put a candidate up against you at the next election.
"It's really about stopping the Labour Party taking power and keeping hold of good eurosceptic Conservatives in Parliament," she added.
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.