In a speech to the 700 delegates in the Bournemouth Conference Centre on Wednesday, Mr Smith is expected to insist on the principle of one member one vote (Omov) in electing the Labour leader and selecting parliamentary candidates. But on Thursday, delegates from both right and left are almost certain to vote to keep the union block vote. Most unions have already voted to oppose Omov.
Mr Smith's only chance of swinging the TGWU's block vote will be an appeal to the union's delegation to the party conference, which has the power to ignore union decisions. His office has hinted that he might make last-minute proposals which union delegations could support.
Speaking on the eve of the TGWU's conference, Bill Morris, its general secretary, offered the chance of a compromise by saying that there was no urgency to make a decison over the selection of MPs until after the Boundary Commission reported, thus leaving time for more discussions until next year's Labour conference. But the TGWU will open a new front against Mr Smith when it calls for the repeal of all union laws introduced by the Conservatives since 1979.
Ties that bind party, page 20