Supervisors of solicitors' offices will have to retrain under a revised practice rule approved by the Law Society Council last week.

But under the long-planned revision to practice rule 13 – the first since it came into force 26 years ago – existing office supervisors will be given 10 years in which to get a minimum of 16 hours Continuing Practice Development (CPD) training.

For office managers appointed after the rule comes into force – expected next spring after approval from the Lord Chancellor's Advisory Committee on Legal Education and Conduct – the new rule will apply straight away.

Council member Sam Wilson, who proposed the change, said the new rule was needed to help tackle default and negligence and to improve management skills to try to bring down the number of claims on the

Solicitors Indemnity Fund. He said there were 9,000 claims paid out this year arising from lack of systems or poor supervision in offices.

An attempt by some council members, led by Geoffrey Sandercock, to amend the rule to exempt existing office supervisors was voted down by a large majority last week.

Sandercock asked the council: “Are we saying to the managing partner in Clifford Chance that he has to go on a qualification course to continue to manage his practice? Or does someone like the Law Society president Tony Girling, managing a Canterbury firm, feel he should be taught how to do his job before he can continue?”

Martin Mears opposed any change in the rule, saying that any modifications could be made by issuing new Law Society guidelines which could come into force immediately.