TONY BLAIR stepped up the pressure on solicitors who plundered compensation for sick and crippled ex-miners, by insisting the money must be paid back.

The Prime Minister threw his weight behind an investigation into firms that have been accused of fleecing former miners of up to £8,000.

He told MPs: "I hope we can make sure that if there is any money unfairly taken from clients, it is returned."

Mr Blair spoke out during Prime Minister's questions in the Commons after the behaviour of some solicitors was condemned by Kevan Jones, MP for Durham North.

In January, the Law Society launched investigations into eight firms, including four in the North-East, against which complaints have been made.

Firms are accused of charging fees to win compensation for ex-miners with emphysema or vibration white finger, even though their legal costs are paid by the Government. Firms have demanded a non-refundable registration fee or have pocketed a slice of any compensation received.

Mr Blair said: "The compensation paid to former coal miners has been of enormous benefit to those people who have suffered very greatly as a result of the work they did."

Mr Jones named Mark Gilbert Morse, of Grey Street, Newcastle, in the Commons, as one firm under investigation.

More than 100 MPs, including several from the North-East, have signed a motion attacking the solicitors.

More than 169,000 claims were received for vibration white finger. Almost 380,000 claims for respiratory disease had been launched by the end of last year. The deadline for claims is March 31.