This week's Deltapoll survey for The Mail on Sunday gave the Conservatives a 15-point lead, up from 12 points last week, with the ruling party on 45 per cent and Labour on 30 per cent.
Johnson now will need to pick up a string of Labour-held seats in northern working-class areas if he is to return to Downing Street with a healthy majority.
The poll suggested that his clear pro-Brexit policy, unlike Corbyn's contortions on the issue, were winning him support in the Leave-backing areas.
A lweek on the campaign train for the Prime Minister has helped his net approval score move back into positive territory, at plus 4 - a thumping 47 points higher than Corbyn.
But if the Labour leader puts in an unexpectedly strong performance during the televised Election debates, starting with his head- to-head showdown with Johnson on ITV on Tuesday night, it could give him a boost.
Meanwhile, the revolt by Nigel Farage's Brexit Party candidates - many of whom pulled out of contests rather than risk splitting the Conservative vote in key marginals - has left his party marooned on 6 per cent, according to the poll.
The poll suggested that most voters thought Farage's political career was nearing its end: a total of 45 per cent said his most successful days were behind him, and just 11 per cent said they were ahead of him.
Deltapoll interviewed 1,526 British adults online between November 14 and 16.
( With inputs from IANS )