While 80 per cent of the Transport and General Workers' Union's pounds 3m political account goes directly to Labour Party coffers, ballot papers and other literature sent to 1 million members will not mention the Labour link.
Under law the T & G, in common with other unions, has to ballot members on its political fund every 10 years, but there is no rule enforcing unions to mention the exact destination of the money.
About 200,000 leaflets sent out as part of the campaign fail to mention Labour and the only reference in a press release yesterday insisted the union's special account was not just a 'party political fund'.
Launching the campaign, Bill Morris, general secretary of the union, said he was 'proud' of the link with Labour. 'It's simply about keeping the T & G in business as a fighting and campaigning organisation,' he said. It is understood, however, that union officials overseeing ballots among all the main union affililates this year, are arguing that the Labour link should not be emphasised.
The T & G will spend pounds 150,000 on a five-week campaign prior to the political fund ballot - which is expected to match the 80 per cent 'Yes' vote it achieved during the last ballot in 1985. At the moment 90 per cent of the 1 million T & G members pay the pounds 3-a-year political levy, of which pounds 1.80 goes directly on affiliation fees to Labour. The AEEU engineering and electrical union, the first Labour affiliate to take a second ballot, won an overwhelming majority last autumn.
Mr Morris said: 'We are pleased to be balloting our members, in contrast to big business which gives millions for its political purposes without any democratic process.'
The ballot result will be announced on 25 March.