Members of David Cameron's cabinet say the Conservative Party will remain unified in support of the prime minister even as some publicly campaign against his stance of remaining in the European Union. In separate interviews on 22 February, Defence Secretary Michael Fallon and Culture Secretary John Whittingdale said Cameron should retain his position, regardless of the outcome of a referendum on EU membership slated for 23 June.

"If the British people vote to leave Europe we will then need to negotiate new arrangements with Europe and actually I think David Cameron is by far the best qualified person to go and do that. He is a very successful prime minister," Whittingdale said. "He is one who I completely support and I see no reason why he can't continue."

Whittingdale is part of a six-member group of cabinet appointees who support a Brexit, highlighting the deep divide in Cameron's Tory Party over Europe. Fallon, although openly a Eurosceptic, has decided to back Cameron's remain campaign. The recent addition of Mayor of London Boris Johnson to the "leave" campaign has called into question whether Cameron can maintain his position as party head.

Fallon said the prime minister should remain in Downing Street. "The work of government goes on. But let me assure you that when it comes to the day after the referendum, on 24 June, that Friday, we'll be back together again delivering the economic and social reforms that we're committed to," he said.

Cameron will try to sell his case for Britain remaining in the EU to parliament on 22 February, facing hostility from his own lawmakers and an exit campaign energised by the backing of Johnson.

One of Britain's most popular politicians, the Mayor of London announced on 21 February he supported leaving the bloc, dealing a blow to Cameron who struck a deal to reform Britain's relations with the EU earlier in February. Johnson's announcement is widely regarded as a step in the direction of Britain exiting the EU. The country saw sterling on course for its biggest one-day loss against the dollar in 11 months while British bond prices also fell.