The Health Service Workers Union (HSWU) says its members have been compelled to endure harsh conditions because of an illegal pension deduction done by the Social Security and National Insurance Trust (SSNIT).

The Union said the deduction at the Trust has reduced the pension entitlement of its members by over 40 percent, a development it described as unfair.

General Secretary of Union, Reynolds Tenkorang told Joy News Tuesday, the already pathetic situation of their members has been worsened by the deduction.

He claims SSNIT has admitted to charging 10 percent annuity each year on the lump sum of members of the Union.

An annuity is a fixed sum of money paid to someone each year, typically for the rest of their life.

Mr Tenkorang said the act is not supported by the PNDC Law 247 of 1991, under which the current Social Security Scheme operates.

"It is an illegality [that] must be stopped," he said.

SSNIT is a statutory public Trust tasked under the National Pensions Act 2008 Act 766 with the administration of Ghana's basic pension scheme. It also caters for the First Tier of the contributory three-tier scheme.

The Trust has over the years been accused of unfairly making illegal deductions from pension packages due retirees.

The HSWU said its members' lump sum has been reduced cumulatively by 41.9 percent and wants the Trust to rectify the situation.

But SSNIT has dismissed the claims, saying the law mandates it to use the average annual salary of the three best years of beneficiaries to compute their pension packages.

Acting SSNIT Corporate Affairs Manager, Victoria Abaidoo said the Trust has been meeting members of HSWU and TUC leadership to explain the arrangement with them.

"It is not that we are hiding anything but because [they] are not working the whole of the 12 months, we will count [their] 12 months backward," she said.