German Chancellor Angela Merkel's spokesman has ruled out any talks on the conditions for Britain leaving the European Union before London has filed a formal notice of its intention to quit the bloc.

"A formal announcement of Great Britain's wish to leave the EU unde Article 50 can only be filed by the UK government. If the government needs a reasonable amount of time to do that, we respect that. But it cannot become a waiting game. One thing is clear: there will be no informal preliminary talks about the term's of Great Britain's exit before Great Britain provides this notification," said Steffen Seibert, German Chancellor's spokesman.