Results of a YouGov survey for 'The Times' showed the 67-year-old leading his rival, Owen Smith, by 62 per cent to 38 per cent.
The 24-point lead will mark an even bigger victory compared to last year, when he secured a 59 per cent share of the vote.
The Opposition leader, who has remained defiant in the face of a coup from his parliamentary colleagues, has majority support among all three groups that are eligible to vote in the contest - full members, registered supporters and union affiliates.
The left-wing leader's lead in the poll comes despite Labour's ruling body winning a challenge against a High Court decision allowing new party members to vote in the contest.
According to the party, around 640,500 members and supporters are eligible to vote in the contest between Corbyn and Smith.
Voting by postal ballot began last week and the leadership race will come to a conclusion when the result is announced on the eve of Labour's annual conference in Liverpool on September 24.
Amid growing animosity between the left-wing and centrist factions of Labour, 39 per cent of those entitled to vote in the leadership election believe the party will split.