The government will effectively be penalising workers who have already been penalised by bad bosses

John Edmonds GMB union head

Unions and an influential employment campaign group, the Industrial Society, have attacked the proposal, warning it will "ration justice" and discriminate against the less well-off.

Backbench Labour MPs, already angry at government plans to introduce greater private sector involvement in the public services, are expected to join the criticism.

The fee is part of a wide-ranging package of measures, published in a consultation document on Friday, designed to reduce the "strain" on the tribunal system.

Tribunal explosion

The number of employment tribunal applications in England and Wales reached 130,000 last year, with three out of four settled out of court.

Employers have backed the government's review, saying it will give all sides more opportunities to resolve disagreements before the tribunal machinery is set in motion. Some want even higher fees to deter employees further.

New proposals include:

Complainant fees In-house dispute resolution procedures Increasing awards where procedures not in place Fast-track system for some cases Fixed period of conciliation

But John Edmonds, general secretary of the GMB union, was adamant that charging workers to bring a case was not the solution.

"Access to industrial justice should be based on need rather than ability to pay," he said.

"For many workers, a charge of possibly hundreds of pounds simply to exercise their rights will be simply too prohibitive."

Patrick Burns, of the Industrial Society, said a better way of "curbing the tribunal explosion" would be to increase funding for the conciliation service Acas.

"Charging tribunal applicants is not the way forward. It will discriminate against low earners and ration justice to the better off," he added.

Charge exemptions

But Employment Relations Minister Alan Johnson emphasised that exemptions to the charge would apply to people on benefits and in cases of genuine need.

"Charging a modest amount would bring a faster and more customer-focused service and also raise funding for improvements in the tribunal and conciliation process," he said.

"At least a quarter of all tribunal applications which come from those who are on benefits or in genuine need will be exempt from any charges.

Alan Johnson: Tribunals are expensive for businesses

"These people will still have access to justice."

However, he went on to stress the "considerable" costs to business of defending tribunal claims, often exceeding �5,000 plus associated management costs as well as the damage to workplace relations.

The government is convinced that many disagreements can be resolved through better procedures in the workplace.

The new proposals included making organisations introduce in-house dispute resolution procedures, and increasing tribunal awards where procedures are not used by an employer.

The British Chambers of Commerce welcomed the review of the current tribunal system, which it described as "ridiculous and costly".

Director General David Lennan said: "We will be consulting employers over the next couple of months to work on the detailed proposals, but feel that the government is moving in the right direction."