Labour is in danger of descending into the kind of "sleazy" politics associated with the Government, according to one of the party's largest and most loyal affiliates.
The warning comes ahead of a hearing in the High Court today in which senior Labour figures clash over alleged ballot irregularities in the selection of a parliamentary candidate for Swindon North.
Davy Hall, president of the Amalgamated Engineering and Electrical Union, said: "If New Labour is to create a reputation for open government and sleaze-free politics, then it must start with first principles. The system for selecting candidates must be democratic and seen to be foolproof."
In today's adjourned hearing an affidavit will be presented by Tom Sawyer, Labour's general secretary, defending the leadership's refusal to re-run the Swindon ballot. He will strongly endorse instead a plan to select the candidate through a panel of the National Executive.
In a contradictory deposition, John Evans, a former party chairman, will argue for a re-run of the vote in which Jim D'Avila, the candidate backed by the AEEU, lost to Michael Wills, a television producer and friend of senior party figures.