Paul Hackett / Reuters
Most give Corbyn odds of 1/6, even shorter than the already-strong odds of 2/7 he had on Thursday.
Owen Smith's odds, on the other hand, have crumbled even further in the same period, down to 4/1 from 7/2.
The surge for Corbyn will be in part thanks to the launch of his re-election bid on Thursday in which he outlined a promise to tackle the "five ills of 21st Century Britain" - inequality, neglect, insecurity, prejudice, and discrimination.
Smith, meanwhile, is still finding it tough to play down his past work as a lobbyist with pharmaceutical giant Pfizer, which some people take as evidence he is not committed to a free and public NHS - an accusation Smith has called "complete nonsense."
In a move reminiscent of one-time Conservative leader hopeful Andrea Leadsom, Smith was also forced to alter his CV on Friday. His website had previously stated that he was a director and member of the UK and Ireland board of Amgen," an American pharmaceutical company.
But Amgen told the Guardian that he was never actually on the board, saying: "Owen Smith's position at Amgen did not give him any involvement or influence on the topics raised here - he was an employee in the
The results of the Labour leadership election will be announced on September 24.
Here are the current Labour leadership odds for both Corbyn and Smith:
- Ladbrokes: Corbyn 1/6 - Smith 4/1
- William Hill: Corbyn 1/7 - Smith 4/1
- Betfair: Corbyn 1/6 - Smith 4/1
- Paddy Power: Corbyn 1/8 - Smith 4/1
- Sky Bet: Corbyn 1/6 - Smith 7/2