Law firms are preparing nervously for the impact of the Criminal Finances Act. This is targeted at, among others, practices whose professionals assist clients in tax evasion. Prosecutors using the act will find it has its challenges – but where a prosecution succeeds there is no limit on the fine.

Such legislation is of a piece with the revelations arising from the Panama and (now) Paradise papers. Data on firms and clients has been thrust into the public domain, whence it cannot be removed.

Influential pressure group the Tax Justice Network last week ‘named and shamed’ nine offshore law firms, only one of which (Appleby, subject of the Paradise leak) lacks a London office. No illegality is alleged but tax ‘avoidance’ (while legal) is becoming a real reputational issue for advisers. One proposal floated last week was that large companies should file tax computations with copies of their legal advice at Companies House, where they would be publicly available.

A criticism sometimes levelled at our commitment to ‘the rule of law’ is that it is a bar that can be set low. Some law firms will steer clients away from aggressive tax planning. The fact remains, though, that it is not the job of a trusted adviser to make subjective moral judgements on what remains within the law. If something must be done about tax avoidance, that is a job for parliament.