England are a general 2/5 (1.40) with the bookmakers to complete their first Ashes victory at Lord's for 75 years after ending day three of the second Test with a lead of 521 runs over Australia.
England dismissed Australia for 215 in the morning but decided against enforcing the follow-on and instead set about extending their lead in quick time.
And while wickets fell regularly, England still ended the day on 311-6 thanks to quickfire half-centuries from Matt Prior and Paul Collingwood.
Australia's target is already over 100 more than has ever been successfully chased in the fourth innings of a Test match, and Ricky Ponting's men are a best-price 12/1 (13.00) with BetFred to complete a remarkable victory.
With a mixed weather forecast over the last two days, though, the draw looks Australia's likeliest means of escape, and that can be backed at 14/5 (3.80) with Paddy Power.
In the series betting, England are now 5/4 favourites with the Australians at 7/4. A drawn series - which would be enough for Australia to retain the urn - is 3/1.