Sir Bill Morris has said Tony Blair should not stand down as prime minister too soon in his third term.

The respected former union leader said on Sunday that Blair "will do what is in the best interest of the party and the country".

He warned that the Labour Party could end up in the "political wilderness" if backbench MPs' calls for Blair to go sooner rather than later were met.

Sir Bill, an ex-general secretary of the TGWU union and seen as close to chancellor Gordon Brown, argued that having just won a third election the prime minister should not drastically break his commitments to the public of serving for a full parliament.

"I do not think the British electorate would be forgiving if we were seen to be rushing to have an internal election," he told GMTV's Sunday Programme.

"There is a small little rump within the Parliamentary Labour Party seeking to rush headlong into the political wilderness of opposition."

He added that he wants to see a successor appointed 18 months to two years before the next election, so that the new leader would have a chance to settle into the job.

And he said that Blair does need to "demonstrate that he is listening" to the electorate.