JEREMY CORBYN made “political history” yesterday after being installed as Labour leadership frontrunner by Britain’s biggest bookies.

Completing a stunning turnaround from 100/1 outsider in May, Mr Corbyn was made favourite by Ladbrokes, William Hill and Paddy Power. And his promotion to pole position came as Unison, which represents 1.3 million public-sector workers, became the latest union to nominate Mr Corbyn. Bookmakers slashed his odds again after the results of a private Labour poll revealed the left candidate is 20 points ahead of his rivals.

It was the third poll in two weeks that shows the principled Islington North MP is on course to shock the political Establishment.

The results sparked another flurry of bets from political punters hoping to back a winner, bookies reported. William Hill spokesman Rupert Adams told the Star: “We have responded by slashing the price from 200/1 into 13/8 — which must be one of, if not the, biggest price cut in political betting history.” Mr Corbyn is set to scoop 42 per cent support in the first round of voting, according to the latest poll seen by the Mirror.

Yvette Cooper is on 22 per cent, Andy Burnham on 20 per cent and Liz Kendall on 18 per cent. The results echo findings from a separate private poll shown to the New Statesman and a YouGov survey of Labour members for the Times, which put him 17 points ahead in the first round. 

Paddy Power made Mr Corbyn a 6/4 shot and revealed half of all stakes taken on the Labour leadership race in the past two weeks have been for Mr Corbyn. A spokesman said: “Some people may still be refusing to take Stormin’ Corbyn seriously, but the punters and the pollsters certainly are.”

Mr Burnham was clinging on to top spot with Coral yesterday, but the firm then shorted its odds on a Corbyn victory in response to the poll to 11/8. Coral said it was “on the brink” of making Mr Corbyn the favourite. 

Coral’s John Hill said: “Andy Burnham has topped the betting for a good couple of months now, but the money behind him in the betting has dried up.”

Further momentum was given to Mr Corbyn’s campaign by a dozen new nominations from local Labour parties (CLPs).

Holborn and St Pancras, represented by Burnham-backing Keir Starmer, was among constituencies where a majority of members backed Mr Corbyn.

He now has 126 CLP nominations, compared to 104 for Mr Burnham, 89 for Ms Cooper and just 14 for Ms Kendall.

Paddy Power said Leicester West Ms Kendall was a “relative no-hoper” at 40/1.