A poll published by Survation shows a 14 percentage point lead over Jeremy Corbyn’s party.
It is the first Survation poll taken since Nigel Farage stood down Brexit Party candidates against Conservative-held seats, a move that was expected to be a boost to Mr Johnson.
Forty-two percent of respondents said they would vote Tory, 28% would vote Labour and 13% would go for the Liberal Democrats.
Five percent would vote for the Brexit Party, which is still standing in seats not won by the Tories in the 2017 general election, 3% for the Green Party and 9% for another party, such as the SNP or Plaid Cymru.
“To correctly judge the effect of parties that have stood down candidates, respondents were read out the names of the parties and candidates that are standing in their own constituency,” Survation said.
Survation polled 1,010 adults between 14 and 16 November.
The pollster has also shown that Boris Johnson is much more heavily preferred for Prime Minister than Mr Corbyn.
The Tory leader was preferred by 47% of respondents, compared to 17% backing Mr Corbyn and 15% want Jo Swinson to take over.
Twenty-two percent said they didn’t know who their preference was.
YouGov gives the Tories a 17 percentage point lead based on fieldwork carried out on 14-15 November, up 3 from its 11-12 November poll.
DeltaPoll has given the Conservatives a 15-point lead over Labour while BMG Research shows a gap of eight points.
In the poll of polls, based on this year’s opinion polling, the Conservatives are on 42%, Labour on 28%, the Liberal Democrats on 14% and the Brexit Party on 6%.