Britain needs to decide who represents it so that its EU exit talks can take shape, French Foreign Minister Jean-Marc Ayrault said on Monday on his way to Prague for post-Brexit vote solidarity talks with eastern European member states.

"Absolutely Britain needs to sort out the problem of who represents it ... from there we can work on an agenda and a calendar," Ayrault said.

British Prime Minister David Cameron, who led the campaign to stay in the EU, has said he will resign. However, he has refused to trigger Article 50 of the EU's Lisbon Treaty, and will stay on for three months while his ruling Conservative Party elects a new leader.

On the subject of single market access that pro-Leave British politician Boris Johnson has said Britain can have without signing up to free movement elements, Ayrault said:

"There are countries with access to the market without free movement. It's the case with . It's not automatic. There are a lot of subjects to discuss.... I think first we need to find out exactly what the British want."