The Law Society is attempting to force Government lawyers to pay for practising certificates (PCs) in a controversial move that could gift the body around £1m a year.

Chancery Lane is lobbying to amend a part of the Solicitors Act that exempts solicitors from the Treasury, the Church Commissioners, the Duchy of Cornwall and any other public department from holding a practising certificate.

The Law Society's decision-making council and the Solicitors Regulation Authority (SRA) are urging peers to incorporate the changes in the Legal Services Bill.

If successful, the move could add an extra £1.2m to Chancery Lane's revenues, given the current PC fee of £950. However, some Government advisers may be able to pay less than the full amount. An estimated 1,650 lawyers currently work for Central Government, of whom 330 pay the fee.

The move is likely to anger Whitehall lawyers and comes after the Government rebuffed a proposed Parliamentary amendment backed by the SRA earlier this month to force all in-house lawyers to pay the fee.

In a statement, the Law Society said: "Government solicitors are subject to regulation, just like solicitors in commerce and industry and local government. There is no sensible argument for exempting Government solicitors from the requirement to hold the certificate and to contribute to the cost of regulation. The current exemption is a historical anachronism, which this Bill should sweep away."