The Conservatives led Labour by 10 points in an online survey conducted last week by pollsters Survation.
The firm revealed the stats at a fringe event hosted by LabourList at the party conference in Liverpool, putting the Tories at 39 per cent, compared to 29 per cent for Labour.
Survation founder Damian Lyons Lowe said that when the polling is applied to revised constituency boundaries, it equates to a 71 seat majority for Theresa May - a huge increase on the Conservatives' current 13 seat advantage.
The pollsters also found that 41 per cent of Labour supporters felt they were further away from the party over the last year.
And 63 per cent said the party is "generally divided". By comparison, the second most divided party was Ukip, which was cited by 26 per cent.
"Across a wide range of issues Labour is doings worse in terms of trust versus how Ed Miliband's opposition was faring in May 2015," Lyons Lowe said.
However, he added that opportunities remain for Jeremy Corbyn's party.
"There are things like the NHS, standing up for the interests of working people, immigration, equality and housebuilding that are either core Labour issues or issues where no party is owning the narrative.
"If Labour is able to present a united front against policies that people care about and cut through, then there is time [to improve]."
Watch: politcal reporter Mark Sands is in Liverpool, where it's a bit gloomy. Weather-wise.