More than three out of four UK companies pay their male staff more than their female staff, and in nine out of 17 sectors in the economy, men earn 10 per cent or more on average than women.

With just days to go before the deadline for all employers in Britain with at least 250 staff to report the difference between what they pay their male and female employees, the numbers published so far provide big lessons for both companies and the government.

The data, the most comprehensive ever collected in any country, do not just reveal the UK’s worst and best-performing employers in the public and private sector, but also the main explanations behind the gender pay gap — and thus some of the most effective ways of closing it.