PLANS to make workers pay to take cases against their bosses to employment tribunals have been branded an "attack on the working poor" which limit access to justice.

The charges, to be introduced by the UK Government this summer, will mean it could cost up to £1500 to take a case to a hearing.

Unions and employment experts have warned the changes to the system will deter people from challenging employers over issues such as unfair dismissal, equal rights, and discrimination complaints.

The proposals will be discussed at the Scottish Trades Unions Congress (STUC) annual conference in Perth on Tuesday, with a motion raising concerns that it will deny workers access to justice.

Employment tribunals came under attack on Friday when Lord Sugar, the tycoon who fronts The Apprentice TV show, condemned what he called the UK's "claim culture". Sugar spoke out after former Apprentice winner Stella English lost a case for constructive dismissal against the businessman.

Ian Tasker, assistant secretary of the STUC, said the coming changes were the latest in a series of attacks on employment rights, which have included extending the time a worker has to be employed before they can claim unfair dismissal from one to two years.

"This is just a denial of access to justice, because people will have to pay to get justice for harm done to them and this is something which is just not acceptable," he said.

At present, taking a claim to an employment tribunal is free. In 2010-11, there were just over 218,000 claims and 2000 appeals, costing the public purse £84.2 million.

The proposed fee structure is expected to involve charges of up to £250 to apply to a tribunal and up to £1250 if the case goes to a hearing.

The Government has said that a system of fee waivers will be available for those who cannot afford to pay. But Tasker said details of this were unclear, and he was not convinced by the Government's pledge that those who cannot afford to pay will not lose out.

"As soon as people see there is a fee attached – especially non-trades union members – they might not even look into the fact they could qualify for this remission to go ahead with their case," he said.

"For example, already a lot of people who might need to seek legal advice don't because of the perceived costs of it."

Employment solicitor Carol Fox, of Edinburgh-based Fox and Partners, said the issue of cost would also be affected by the fact that tribunal claims have to be submitted within a certain time period.

Fox said that in an unfair dismissal case a claim has to be made within three months of the date of termination of employment. "There is a very short window to act to protect your legal position and by introducing fees it is going to make it much, much harder," she said.

She believes the fees could be challenged under European and human rights law because they will make it more difficult to access justice.

"European law requires ... proportionate means of accessing justice and being able to take equal pay and particularly discrimination complaints," she said.

"We intend to challenge these new rules and ensure there is no restricting access to justice for people who are already in difficulty in the workplace."

Jim McCourt, manager at Inverclyde Advice and Employment Rights Centre, said it would impact on many of his clients. He added: "It is a further attack on employment rights, particularly for the working poor. The tribunal system is no longer going to be an option for the vast majority of the working poor – that is the bottom line."

Lynn Walsh, head of law for the Equality and Human Rights Commission in Scotland, pointed out that when employment tribunals – formerly industrial tribunals – were established, the aim was to make them "easily accessible, informal, speedy and inexpensive".

She said: "We are concerned that these fees will deter people who have been discriminated against from making claims. Access to justice should be available to everyone, and not just those who can afford it."

A Ministry of Justice spokeswoman said: "It is not fair on the taxpayer to foot the entire £84 million bill for people to escalate workplace disputes to a tribunal. We want people, where they can afford to do so, to pay a contribution."