The survey by The Independent found that the Conservative lead over Labor has fallen to 12 percentage points, down from 21 points.

The poll comes at a critical time for Brown, who opened the Labor Party Conference in Manchester by calling for unity, The Times of London reported.

"Testing times like these are not about public relations and it's not about slogans," he said. "The real test is of your judgment. The real test is of the decisions you make."

YouGov polled party members for the Times and found that 60 percent do not believe that Brown can lead Labor to an election victory. Foreign Secretary David Miliband is the favorite of those who would like to ditch Brown as party leader.

Brown enjoyed a brief honeymoon when he succeeded Tony Blair. More recently, the party has endured low poll numbers and embarrassing losses in by-elections, including one where Labor was outpolled by the left-wing Greens and right-wing British National Party.