There should be no distinction in remuneration for those who undertake the same roles within the workplace. Where employees are engaged in "like work" they should received equal pay, irrespective of whether they are male or female. "Like work" covers work which is equal in relation to the level of effort, skill or decision making required to undertake it.
The issue of Equal Pay is regulated by The Equality Act 2010 and covers such matters as basic pay and overtime. An employee can write to their employer seeking details of how their pay is calculated and for disclosure of material which may assist in the employee demonstrating they are not receiving equal pay. Claims can still be raised up to 6 months after leaving employment.