A YouGov survey for The Sun suggested that with David Cameron in charge 34% of people would vote for the Tories, while 40 per cent would vote Labour.
However when asked the same question if Boris was the Tory leader, the Conservatives secured 37%, while Labour’s rating fell to 38%.
Boris is increasingly being taken seriously as a potential leader of the Tories, with a poll conducted by the Conservative Home website earlier this week showing 32% of party members wanting the mayor to succeed Cameron.
Although a subsequent poll conducted by the site published today showed that the prime minister is the overwhelming favourite of party members to lead the party into the 2015 general election.
The findings come as Boris basks in London's Olympic sun, with even getting stuck flailing mid-air on a zip wire seemingly unable to dampen his mood.
And Boris was given partial credit for the success of the London Games by Rupert Murdoch on Thursday morning, who tweeted: "London in best shape ever. All overboard about the Olympics, brilliantly organized by Zeb [Seb] Coe and Boris Johnson."
Murdoch and Boris are due to make a very public appearance together tomorrow, after the mayor invited the chairman of News Corporation to watch the 800m swimming final at the Games.
Their show of mutual affection contrasts with the frosty relations between Murdoch and Cameron in the wake of the phone hacking scandal and the creation of the Leveson Inquiry into press ethics.
One obvious barrier to Boris succeeding Cameron as Tory leader is his pledge to serve a full term as Mayor of London, which would keep him in City Hall until 2016.
However there is a precedent for the mayor also holding a Commons seat. Ken Livingstone overlapped in both roles for a year between 2000 and 2001.
OP: China? The USA? The biggest winner of the Olympics could well be Boris Johnson. The average Japanese person or someone in Australia might not know David Cameron but footage of Johnson arsing about has probably reached them because of the Olympics. I think this is the stage he craves. The Rupert Murdoch endorsement could yet capsize it all though.