Irwin Mitchell's turnover grew 12 per cent last year, with a 3 per cent average increase in PEP, with the result that the margin was pushed down to 23 per cent. The firm did not add any new partners between 2004 and 2005, maintaining its partnership of 83, of which 48 are equity partners. Organic growth, rather than lateral hires, is key to Irwin Mitchell's strategy.

Just 258 of its 837 fee-earners are qualified lawyers; the rest are other legally trained staff such as paralegals. Many are kept busy with Irwin Mitchell's volume business, processing personal injury claims. This area remains profitable, although managing partner Howard Culley admits that, in the current climate, margins in volume work are being squeezed. The profile makes Irwin Mitchell an oddity in the top 25 corporate and commercialdominated firms.

Around 80 per cent of Irwin Mitchell's turnover is derived from contentious work, much of that insurance and insolvency-related, as well as clinical negligence, work.