Half of Labour constituency chairmen do not expect Tony Blair to serve a full third term, according to a new poll.

The survey, conducted by ePolitixPlus, finds that 46 per cent of local chairmen do not expect the prime minister to be in place at the end of a historic third Labour parliament.

The random survey of 50 Labour chairmen will add to speculation that Blair will stand aside after delivering a hat-trick for Labour.

It will also fuel the Labour leadership race which has been thrown open following Alan Milburn's return to frontline politics.

The poll comes in the wake of reports that Tony Blair "wobbled" earlier this year.

According to Lord Bragg the prime minister nearly quit for personal family reasons, a claim disputed by Cherie Blair in her first live TV interview on Thursday.

The survey also raises questions about the future of party conferences.

Nearly 40 per cent of Labour chairmen surveyed do not believe the seaside events engage voters.

But three out of four polled maintain that the party conferences influence public opinion.