Mr Dromey said: 'Our view is that those who have left their union should return to Unison. We are doing everything possible to persuade them to go back. The T&G is built on progressive trade union principles. We never have, nor will we ever, poach the members of another union.'
Staff left Unison to join the rival union after a row between manual and white-collar representatives at Unison's Middlesbrough branch. The breakaway workers claim they are formally members of the Administrative, Clerical, and Technical Services section of the T&G. They have an office at Middlesbrough, the council has recognised the new branch and it has 700 members, activists claim.
'As far as we're concerned the T&G has to accept us into membership,' said Simon Clark, an officer of the new branch. Julia Rostron, another leading breakaway member, said she had a steward's card signed by the T&G regional officer.
Some breakaway members specified on their application forms for T&G membership that they would take legal action if rejected, according to Ms Rostron.
If the T&G takes on new members, Unison could declare a dispute and ask the Trades Union Congress to arbitrate. TUC rules state the T&G could be liable to pay Unison compensation for lost membership fees for up to two years for poaching its members.