Clifford Chance (CC) has become the first magic circle firm to include equity partners in its gender pay gap report.

The firm's report reveals that the mean gender pay gap for the whole of its London workforce, including all partners and employees, is 66.3% in favour of men, while for partners alone, the gap is 27.3%.

While law firms are not required to include partners in their gender pay gap reporting, CC said it had chosen to provide the information as it wants to "accelerate change".

The firm's report adds: "We hope other law firms will take an equally transparent approach, and we expect their figures to show a similar gap when partners are included."

CC's report also reveals that it has a pay gap of just 3.9% at associate level, with a 27.7% gap for business services staff.

Disregarding partners, the firm's pay gap for all employees is 20.3% in favour of men, with male staff receiving bonuses on average 53.2% higher.

UK regional managing partner Michael Bates described the decision to include partner data as being "about doing the right thing". "Whilst including our partnership in adjusted results shows a larger gender pay gap than the data from the statutory reporting requirements, our decision to publish these figures demonstrates our commitment to closing the gap and accelerating the pace of change of our gender demographic at every level," he said.

"We hope the government will provide greater clarity going forward on the inclusion of partner data, and that other professional services firms will demonstrate their commitment to addressing gender issues by adopting an equally transparent approach."

CC is the last of the magic circle to publish its pay gap report. Of the group of five firms, it has the second largest pay gap for non-partners after Linklaters (23.2%). Last week, Freshfields announced the smallest gap at 13.9%.

With regards to bonus pay, 55.9% of CC's female staff received a payout for the year covered by the report, compared to 55.1% of men.

UK law firms have come under increasing pressure to include equity partners in their gender pay gap reports, which all UK organisations employing more than 250 people are required to file by 4 April.

To date, just a handful of other major law firms have opted to disclose details of partner pay, including Reed Smith, Irwin Mitchell and Norton Rose Fulbright, which published a combined London office figure alongside breakdowns for equity partners, associates and staff.

Yesterday (26 March), Pinsent Masons issued revised numbers that include partners after originally publishing data that only covered non-partner staff. The firm added that it will be "engaging with the Law Society and other City law firms to seek their support in making representations to government to make changes" to what firms are required to report.