The chairman of the Parliamentary Labour Party is facing a challenge from another backbencher who would use the job to air the grievances of grassroots supporters.
Andrew Mackinlay, the Labour MP for Thurrock, said last night that he had been approached by colleagues who wanted him to stand against Clive Soley, but said he had not yet made a decision.
Mr Mackinlay is a member of the Parliamentary Committee, which is made up of backbenchers and senior ministers and which Mr Soley chairs in his role as the leader of Labour's backbenchers.
Mr Soley, who has been chairman of the PLP since 1997, is seen as a Blair loyalist, but Mr Mackinlay has challenged the Government, particularly over the pace of modernisation in Westminster.
Some Labour MPs believe Mr Soley has acted as Tony Blair's voice on the back benches. They would like to see a PLP chairman acting more as a "shop steward", in the same way that the former Conservative 1922 Committee chairman Sir Marcus Fox worked, voicing Tory MPs' concerns over the direction of the previous government. If he decides to stand against Mr Soley, Mr Mackinlay's challenge will be put to Labour MPs in November. He would face a tough fight in a parliamentary party that is still overwhelmingly loyal.
"I am pretty heavily committed and believe it or not I don't go looking for trouble," Mr Mackinlay said. "It is true that I am thinking about it ... I have not made up my mind yet."
Mr Soley has not faced a challenge before, though last year there were suggestions that Gerry Sutcliffe, MP for Bradford South, would stand.
One PLP source said last night that he did not expect a serious challenge to emerge before the general election. "I think what we would say is that Andrew will fly his kite and the flutters in the wind will be so gentle that it will be back down to earth very quickly," the source said.Reuse content