The Prime Minister was forced to point out that the "Conservative party does not do pacts and deals" in response to Nadine Dorries MP's suggestion that she may run on a joint Tory-UKIP ticket in the next election.
He said that his party intended to win the election "outright".
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.