As firms are forced to reveal sexes’ hourly wages...

Finance, banking and airlines have some of the worst pay gaps.

Ryanair reported a gap of 72% – this means women earn 28p for every £1 men earn – and easyJet 51.7%.

This reflects the fact that the majority of their pilots are male and are among the companies’ highest earners.

This is also reflected in football clubs with Manchester City reporting a pay gap of 87.7%.

Barclays International reported 48%, RBS was on 37.2% and Virgin Money 32.5%. However, in a few organisations women are paid more than men.

At Unilever, for example, women earn 9% more than men. At Channel 5 the pay gap is 2.85% in favour of female staff and at the British Museum men and women are paid exactly the same.

Mirror Group Newspapers, publisher of the Daily Mirror, had a gap of 20.7%. Women are more likely to be employed in lower-paid and less skilled jobs.

Campaign organisations such as the Fawcett Society say women have to balance their work responsibilities with caring for children or elderly relatives.

As a result they are more likely than men to take part-time posts. Taking a career break such as maternity leave means women can have less opportunity for career progression or see their salaries stall.

The culture of the workplace is also a factor. The majority of senior positions paying the highest salaries are occupied by men.

Women also face greater discrimination. The Equality and Human Rights Commission found one in nine new mothers were either dismissed, made redundant or treated so badly they ended up leaving their job. The PayMeToo campaign is encouraging women to raise unfairness with bosses and work together to end pay discrimination.

Backed by MPs from all major parties, it says you have a right under the European Convention on Human Rights to talk to colleagues about what they earn.

Women should also talk to their managers if they believe they are underpaid and demand their company publishes an action plan to address any gender pay gap.

Women are also encouraged to join a union and set up a Women’s Network at their place of work.