Solicitors who charged miners for "free" compensation advice are being urged to pay the money back.
The fund is one of the world's largest personal injury schemes
An independent review into a billion-pound injury scheme has called on the legal profession to deal with the issue of refunds.
The energy minister and two Labour MPs have backed the review - saying it is up to solicitors to take action.
But a Law Society spokesman told the BBC that it does not have the power to force solicitors to pay the money back.
The independent review by Stephen Boys Smith, a former official in the Home Office - prepared for the Department of Trade and Industry - was backed by energy minister Malcolm Wicks.
It acknowledged some solicitors and trade unions deducted costs from claimants, even though they were already being covered by the government.
But the minister said the matter should be taken up by the legal profession - not the government.
The government scheme is expected to pay a total of almost £5bn to former miners who became ill after working underground and handling heavy drilling equipment.
Bassetlaw MP John Mann said: "It is a rap on the knuckle for solicitors - I want to see a systematic way of getting people their money back - to date we have had to fight it case by case.
"On the back of the independent inquiry, solicitors should do the decent thing and pay back immediately."
Not 'crystal clear'
Paddy Tipping, MP for Sherwood, said: "I feel we are lining the pockets of solicitors, lawyers, trade unions and professional advisors - they are doing well out of the scheme while men who are sick and old are still waiting for their money.
"It is not fair, it is not right and we need to do better."
Geoffrey Negus of the Law Society said: "We have been using our powers to the maximum extent possible to make sure that solicitors comply with their professional obligations."
He said the society is willing to meet with the government but added that it does not have the power to order solicitors to pay the money back.
Mr Wicks said: "Although there are lessons to be learned, no major changes are needed to improve the running of the schemes and that the fraud procedures in place are appropriate."
However, he said some claimants did appear to have been invited to make contributions without it being "crystal clear to them" that such donations were a matter of choice.