You do, don't you? I thought so. You reckon that your boss is paying more to other employees of opposite gender to you for performing the same or substantially the same duties as you. You may soon be able to find out if they are without the boss knowing that you are checking up on them.
New laws which came into force on 6 April 2017 compel employers with at least 250 employees to publish annual information which is designed to show whether there is a difference in the average pay of their male or female employees. The first publication must be made by 5 April 2018 on the employer's website and in a way which is accessible to all its employees and to the public. Government departments, the armed forces and other public authorities are excluded from these laws but worry not because they are caught by similar legalisation which came into force on 31 March 2017 and must be complied with for the first time by 30 March 2018. This will benefit around 3.8 million employees in England alone.
If you don't believe me or want to own more then devour the Equality Act 2010 (Gender Pay Gap Information) Regulations 2017 SI 2017/172 and the Equality Act 2010 (Specific Duties and Public Authorities) Regulations 2017 S1 2017/353.