Women solicitors salaries are paid up to £4,000 less than their male counterparts, according to a Law Society survey.
Figures released this week show a £2,340 difference in comparable pay between female and male assistant solicitors.
That figure rises to a difference of nearly £4,000 between the earnings of male and female salaried partners.
Women solicitors are also less likely to work in the larger and more profitable firms but more likely to do legal aid work, says the survey.
The survey of 600 firms has dismayed Law Society president Tony Girling, who with Equal Opportunities Commission chair Kamlesh Bahl is writing to every firm to ask then to re-examine their remuneration policies and draw their attention to the EOC's Equal Pay Code.
Girling said he did not believe firms were pursuing a premeditated policy of pay discrimination but rather that the figures revealed unconscious or historic practices.
However, Macfarlanes partner Jane Whittaker and Linklaters & Paines partner Diana Good insist that pay discrimination is not a problem in the City where, they believe pay rates are based solely on skills and experience.
Whittaker, a former chair of the Women's Solicitors Association, suggested female solicitors in regional law firms were more isolated than their counterparts in the City and therefore unable to compare pay levels with each other.
Good added that the Law Society had to take strong action to confront firms who were paying their female fee earners a lower wage.