The High Court ordered local government workers to call off a highly disruptive month-long strike because their union had 'promoted' the industrial action.
Leaders of the National and Local Government Officers' Association will today appeal against a ban on the stoppage at the London Borough of Newham, ahead of a hearing at the Court of Appeal.
Phil Thompson, chair of the union's Newham branch, said yesterday's decision potentially outlawed any union campaign for a 'Yes' vote in a strike ballot.
Council officials, however, said that the High Court ruling by Mrs Justice Ebsworth was given because the original industrial action in the poll tax section was taken without a ballot.
Newham undertook last night not to take action against the union for contempt of the court order to call off the strike immediately.
The union called the strike, involving 10 per cent of the council workforce, on 3 August after balloting its 2,500 branch members about compulsory redundancies in the poll tax collection department and after a threat to sack any strikers. About 63 per cent of union members voted in favour of an all- out indefinite strike. All those called out are receiving full pay from Nalgo.
The council argued in court that it had offered jobs to the three staff members at the heart of the dispute and promised not to take any action against those involved in official industrial action.
It had met the demands over which Nalgo had balloted its members and there was no longer justification for the strike.
Yesterday Mrs Justice Ebsworth said she was unable to accept that all the issues had been resolved.
There was still a dispute about compulsory redundancies, although now it was confined to narrow issues relating to the terms and conditions on which permanent employment should be offered to the three officials affected.
But it appeared that the council had made much more of an effort to settle the dispute than the union.
The 'balance of convenience' in deciding whether or not the strike should be allowed to continue, pending any further court action, was 'firmly in favour' of the council.
Newham moved for a court order halting the strike, which has had a severe effect on local services, after launching an action for damages against the union.
The judge said it was 'clearly arguable' that the union had 'promoted' the strike call before the ballot on industrial action took place at the end of July and was therefore in breach of trades union legislation.