British Prime Minister Theresa May has launched negotiations with the leader of the country's main opposition Labour party in a last-ditch effort to reach a compromise over the terms of Britain's departure from the European Union.

But although Mrs May's highly unusual move of seeking the opposition's support for Brexit - as the process of the country's separation from the EU is popularly known - has surprised political observers in a country accustomed to sharp confrontations between government and opposition, doubts persist over the leaders' ability to end a crisis which has paralysed Britain for months.