The Legal Services Commission has called for more criminal lawyers to take part in its scheme to test different methods of assessing advocacy, after too few practitioners signed up.

Piloting of the Quality Assurance for Advocates (QAA) scheme began in February at Crown courts in Birmingham, Cardiff, Inner London and Winchester, and will end in August.

Although 220 solicitors and barristers have agreed to take part, the LSC needs another 30.

It said there is a particular need for female volunteers as well as ethnic minority advocates, those who work part-time or with caring responsibilities, and advocates with a disability or health problem.

The pilots will try out assessment options including multiple choice tests, portfolio examination, simulated advocacy and judicial evaluation.

Results of the pilot will be published in October, in advance of a consultation on proposals for a QAA scheme in early 2010.