Last year, the company signed an agreement to give staff a two-part pay rise, with the first award given in 2001, followed by another 3% this year. But according to Donald Place, joint secretary of the Leeds and Central Yorkshire GPMU branch, Polestar has refused to pay its 2002 increase.

GPMU deputy general secretary Tony Burke was called in for meetings with the company last week, but a conclusion has yet to be reached and discussions are still "liquid".

Burke added that Polestar Petty had been having difficulties since it lost a major contract last year.

Polestar declined to comment, but said it was in negotiations with the GPMU.