One of Britain's leading bookmakers had decided the election outcome is so certain it has begun paying out bets on a Labour victory.

In a surprise move Ladbrokes announced its decision early on Monday morning with a press stunt on College Green, Westminster.

A lone jockey, dressed as Tony Blair, headed for the winning line for a different kind of photo-finish because as far as Ladbrokes is concerned June 7 is a one-horse race.

Using racing slang the company said that Tony Blair, dubbed by satirists as the "trendy vicar", is now "in another parish" - he is so far ahead there is no contest.

Ladbrokes had cut Labour's odds to 1-50 before taking the unprecedented step of paying out - a move which it claims will cost them up to £300,000.

Spokesman Sean Boyce said the company would now encourage punters to spend their winnings on new bets such as the size of Labour's majority.

"We've taken the plunge and decided to pay out. Of course if William Hague does cause an upset we'll end up paying out twice," he said.

The company is proposing that the phrase "Blaired in" which they claim is already being used at some race courses to describe a foregone conclusion should be entered into the Oxford dictionary.