After Brexit: Roadmap for a leap in the dark

A supporter speaks to a passer by during a Vote Leave event outside the Chelsea Flower Show in London, Britain May 28, 2016. REUTERS/Neil Hall

BRUSSELS (Reuters) - Dawn, Friday, June 24. The votes are in. The British have spoken in their EU membership referendum and they want out. It is a scenario European leaders are now planning for in earnest while praying it never happens.

Secret meetings in Brussels and across Europe reveal huge uncertainty, officials and diplomats familiar with the proceedings say, over what would follow a vote that British Prime Minister David Cameron calls a "leap in the dark" -- and also no little concern about what happens if Britain stays on.