Women have effectively worked for free so far this year when compared to the average man, according to a new report commissioned by the union movement peak body.
The TUC said its analysis suggested the 13.1 per cent pay gap means that the average woman effectively works for free for nearly seven weeks compared to the average man.
Women effectively stopped working for free on Sunday, the study indicated.
The wage difference is because women tend to be employed in lower-paid jobs and are more likely to work part-time as they deal with caring responsibilities, said the TUC.
The union organisation said the gender pay gap has remained “stubbornly high” for years and was higher in professions dominated by female workers, such as healthcare and social work as well as sectors including finance and insurance.
The research found that women aged 40 to 49 have a gender pay gap of 16.5 per cent, rising to almost 19 per cent for those aged between 50 and 59.
TUC general secretary Paul Nowak said everyone should be paid fairly and women do not deserve to be treated as “second class” workers.
He added: “The Employment Rights Bill can help to close the gender pay gap by banning exploitative practices like zero-hours contracts that hit women the hardest, and introducing fair pay agreements will boost pay and conditions in social care which has a female-dominated workforce.
“Government policy to make employers publish action plans for tackling their gender pay gaps can also make a real difference.”