The new findings, published today by the Law Society, will confirm fears among legal women's groups that their members are being treated as second- class workers in the legal profession.
The average pay for a female partner of a law firm is now pounds 30,000, while a man can expect to earn pounds 43,000. At the top end of the profession, a successful woman partner working in a commercial law firm receives pounds 55,368, while a man with similar qualifications and experience will pocket pounds 8,000 more.The difference in pay between a male and female partner at a typical small, country practice is only pounds 5,000.
Attempting to explain the difference between the pay regimes, the Law Society's report said: "The gender differential in remuneration may, in part, be accounted for by differences in years of post-qualified experience and solicitors' areas of specialism."
But some women lawyer groups believe the difference has more to do with indirect discriminatory pay structures. Many firms do not make it easy for women solicitors to return to the same pay grades after breaks to care for children. Although at entry level to the profession half of newly qualified lawyers are women, by the time they reach partner status the proportion has fallen to around 15 per cent.
There is now a widely held belief that there is a glass ceiling holding women back because so few make it to the top. Of the leading 20 law firms, not one has a senior female partner and only one has a woman as a managing partner.
Last week a survey of the top 100 law firms revealed that commercial lawyers were breaking new records in profits. The Lawyer magazine's 100 survey, a comprehensive analysis of law firms' gross fees and partner profits showed total fee income had broken through the pounds 5bn barrier for the first time.
But today's Law Society survey of 554 firms around the country tells another story. A quarter of those solicitors who own their firm receive less than pounds 25,000, while those in a quarter of firms with 26 to 80 equity partners earn pounds 248,298 or more.
The survey also found that the average pay of an assistant solicitor was pounds 22,500. But the Law Society also acknowledged that legal services now contribute pounds 791m to the United Kingdom's invisible earnings.
Commenting on the latest figures, Robert Sayer, president of the Law Society, said: "We welcome the continuing economic success of commercial law firms which provide world class quality legal service in a highly competitive international market. Their contributions brings greater benefit to the economy in terms of jobs and prosperity."