Jeremy Corbyn's victory in the Labour leadership race is a "done deal" according to one bookmaker which has already started paying out on bets.

Paddy Power said the veteran left-winger is now certain to win and it is paying out £100,000 in the "biggest upset in political betting history".

Mr Corbyn began the race as a 100/1 rank outsider but over the summer has stormed to the front of the race, seeing his odds tumble to 2/9 and attracting 80% of bets in the last two weeks.

Former Labour prime ministers Tony Blair and Gordon Brown have joined other party grandees to warn of the dangers of electing Mr Corbyn.

But Paddy Power are now paying out on bets made on Mr Corbyn succeeding Ed Miliband and beating early favourite Andy Burnham and frontbench rivals Yvette Cooper and Liz Kendall.

A spokesman for the bookmaker said: "In our eyes it is a done deal.

"Storming Corbyn has notched up the W. We are paying out six figures.

"It is the biggest upset in political betting history."