Islington North MP Jeremy Corbyn is now the odds-on favourite to win the Labour Party leadership.

Bookies slashed their odds after a YouGov survey of 1,411 eligible voters gave Mr Corbyn 53 per cent of the vote. This would be enough to win the contest outright, without the need to count second preferences. Nearest challenger Andy Burnham received 21 per cent.

The poll was announced on Monday, and Peter Spencer, of Betfred, said this was followed by a “surge” of 11th hour bets in London - and in particular Islington - totalling over £10,000.

Mr Corbyn had started the contest as rank outsider, and William Hill spokesman Graham Sharpe said: “We can recall no other example of a 200/1 chance becoming an odds-on favourite in a political betting market in our 50-plus year history of political betting.”

YouGov president Peter Kellner said he “would personally be astonished if Corbyn does not end up as Labour’s leader”, despite voting not starting until Friday and the result not being declared until September 12.

Mr Corbyn urged caution today, but did say his campaign is going “very well”.