A SUPERMARKET may have to pay hundreds of thousands of pounds in compensation to North-East workers if a landmark employment tribunal rules it discriminated against trade union members.

Asda is accused of breaching a law that prevents employers offering inducements to workers in order to bypass collective bargaining procedures with a trade union.

It is the first case to reach an employment tribunal since the law changed in 2004 after the UK was found to be in a breach of the European Convention on Human Rights.

The law then allowed employers to discriminate against trade union members by offering inducements to surrender trade union rights.

In January last year, Asda offered workers at its Washington depot, on Wearside, a deal, which it called The Modern Alternative.

The benefits included an immediate pay rise of at least ten per cent, higher rates for late and night shifts, double time for bank holiday working and increased sick pay entitlement.

The deal, which all employees were entitled to vote on, was not negotiated with the GMB union, which had a long-established collective bargaining agreement at the depot.

In a leaflet given to employees containing questions and answers about the offer, Asda said it would not be possible for anyone to remain on the existing terms and conditions, if the majority voted for the new deal.

If the deal was rejected, Asda said, employees would stay on existing conditions and none of the Modern Alternative features, including the pay rise and higher shift rates, would be introduced.

To explain the motivation, Asda said the scheme would mean "an end to the 1970s- style collective bargaining" and that workers would, for the first time, have a direct say on their pay and conditions "rather than the unions".

GMB regional officer Michael Hopper said: "One might think that an employer would be happy to keep the wages bill lower, so what else could have been the motive?

"When I questioned that the offer had to be put to the workforce without the removal of collective bargaining, I was told the offer was conditional on surrendering collective bargaining."

The tribunal, Davies and Others versus Asda, starts today in Newcastle and is being brought on behalf of 341 GMB members.

An Asda spokesman said last night: "The GMB were involved every step of the way. The offer was rejected and so nothing has changed.

"We are very disappointed that this tribunal has been brought."