The attorney general’s office is one of Whitehall’s worst offenders in terms of gender pay parity, according to research by the Guardian newspaper. Women civil servants at Jeremy Wright QC’s department are paid an average of £36,250 while men get £61,240, according to analysis of data from the Office for National Statistics.

The AGO has relatively few staff (about 40) and therefore small movements can skew the statistics, the research acknowledges. Yet the gap has widened by 18 points in the last decade, to 41%.

A spokesperson for the office said: ’In a very small organisation like AGO, minor changes in staffing can lead to significant changes in percentages so we do not believe too much can be read into these statistics. We are strongly committed to diversity: our two most senior members of staff are women and over half of the Executive Board are women.”

The AGO has recently appointed a diversity champion and said it has policies in place to encourage female applicants for roles and to ensure equal treatment of candidates.

The average gender pay gap across all government departments and agencies is 13% (with men earning an average of £28,280 and women £24,680). The Ministry of Justice doing slightly ‘better’ at 11% (excluding agencies).

Since 2008 the pay gap has widened at 23 of 97 government departments or bodies. These include the Supreme Court (14% wider).

A Cabinet Office spokesperson quoted by the paper said: ’The most recent ONS report shows that overall, the civil service gender pay gap has narrowed, but in small organisations it is very sensitive to minor changes in staffing. The pay gap is affected by differences in seniority, profession and regional distribution of staff, which can be very different across departments and are not controlled for in the raw data.

’In autumn this year we will be launching our new diversity and inclusion strategy, which outlines plans to achieve our aim of becoming the most inclusive employer in the UK by 2020. The strategy will set out how we will continue to improve the gender balance of the civil service at all levels.’