Willis has the biggest gap across the consultancies ranked by Corporate Adviser, with a 39.8 per cent gap, although Towers Watson, the legal entity that contains the human capital and benefits business, has a gap of 36.7, putting it just behind Arthur J. Gallagher, which had a 38.4 per cent gap, and Aon UK at 37.9 per cent. However, Towers Watson had the highest percentage of women in the top quartile of earners, with 40 per cent of higher earners being female.
JLT Benefit Solutions has the second-smallest mean pay gap at 19.9 per cent.
The figures cover 2017. All companies with 250 employees or more must publish their gender pay gap by tomorrow.
The Office for National Statistics says that the finance and insurance sector has the biggest mean pay gap across the UK workforce, standing at 35.6 per cent.
| Firm | Average gender pay gap (%) | % of women in higher paid jobs | % of women in lower paid jobs |
| Barnett Waddingham | 11.4 | 35.1 | 61.2 |
| JLT Benefit Solutions | 19.9 | 30 | 58 |
| Hymans Robertson | 20.1 | 35 | 70 |
| KPMG | 22.1 | 33.2 | 56.1 |
| Lane, Clark & Peacock | 25.7 | 40 | 64 |
| Capita Life & Pensions Services | 26.2 | 28.2 | 57.3 |
| Aon Consulting | 28.4 | 31.6 | 70.9 |
| Mercer | 32.3 | 33 | 64 |
| Aon Hewitt | 33.7 | 24.8 | 58.9 |
| Pricewaterhousecoopers | 34.4 | 36.7 | 88.2 |
| Towers Watson | 36.7 | 57 | 28 |
| Aon UK Ltd | 37.9 | 20.3 | 54.6 |
| Arthur J Gallagher Services (UK) | 38.4 | 19.3 | 65.1 |
| Willis Limited | 39.8 | 21 | 54 |