Disabled workers in Britain are paid nearly 3,600 U.S. dollars a year less than their non-disabled work colleagues, an analysis by the country's biggest trade union organisation, the TUC, revealed Monday.

It means people with disabilities are on average paid 15.2 percent less, with the pay gulf even wider for people with mental illnesses or depression, added the TUC.

The TUC called on the government to make it compulsory for employers to publish their disability pay gaps.

The call came just days after government ministers published a voluntary code to encourage employers to disclose the number of disabled people they employ, their career progression and pay.

But the TUC said that without a legally-binding requirement on companies to publish their pay gaps, progress will be too slow.

It added that more needs to be done to remove the barriers facing disabled people in the workplace.

"Just half (50.5 percent) of working-age disabled people in the UK currently have a job, compared to four-fifths (81.1 percent) of non-disabled people. For some disabled people the problem is even worse," said the TUC, with figures showing only 3 in 10 (30.4 percent) people with a mental health disability are in work.

The TUC wants the government to introduce a statutory requirement for employers to report on their disability pay gaps and employment rates, and to publish action plans setting out how they will address them.

TUC General Secretary Frances O'Grady said: "Disabled people face the double whammy of poorer job prospects and lower pay. Paying lip service is not going to fix the problem."

"Employers must be legally required to publish their disability employment and pay gaps. A light-touch, voluntary approach simply won't cut it. Large companies have to report their gender pay gaps. Disabled people deserve the same level of transparency."