West Northamptonshire' s gender pay gap means women will effectively work for free for the rest of this year, figures suggest.
Campaigners have called on the government to act after data revealed a 'worrying' difference in earnings between men and women across the UK.
Estimates from the Office for National statistics show that, as of April, female workers in West Northamptonshire were paid an average of £12.68 an hour while their male peers received £15.34. That is an overall pay gap of 17 percent.
Over the course of the working year, that means women in the area will be working for nothing from October 29.
Nationally, the female workforce is paid a median hourly rate of £12.92 – 15 percent less than the £15.27 hourly wage earned by men.
For full-time workers, the gap is almost eight percent.
Hourly figures are used to remove the effect of overtime, while the median is used to stop them being skewed by particularly small or large wages.
The ONS said estimates for this year are subject to some uncertainty due to challenges faced collecting data during the coronavirus pandemic but the figures suggest the gap for full-time workers has widened slightly nationally since April 2020.
And with women said to have been disproportionately impacted by the coronavirus pandemic, campaigners believe the problem of unequal pay could worsen.
Sophi Berridge, from The Equality Trust, which campaigns to reduce income inequality, said: "During the pandemic, women were more likely to be furloughed or made redundant, suffered from the lack of childcare and took on greater responsibilities of home-schooling and care work.
"The slight increase to the gender pay gap indicates there remains a continuing and pressing problem."
She said employers should consider introducing subsidised childcare, access to paid time off for both parents and robust training and support for women.
Felicia Willow, interim CEO of gender equality charity The Fawcett Society, wants 'bold action' from government.
She added: "Whilst gender pay gap reporting has been effective in getting big employers to act, it needs to go much further.
"We want to see government requiring mandatory action plans from employers to tackle gender pay gap in the workforce, as well as sharing data.
"The pandemic has had a tough and disproportionate impact on women, in particular women of colour, disabled women and mothers.
"And now in addition to this, a widening gender pay gap paints a worrying picture."
The gender pay gap is the estimated difference between the average hourly wage for men and women across all jobs and is different from the concept of equal pay, which means men and women doing the same job must be paid the same.
A spokeswoman for the government's Equality Hub said the pandemic had had a serious impact on the work-place and wider economy and will continue to do so.
She added: "The government will continue working to make the UK a fairer place to live.
"We are committed to making work-places more equal to allow everyone to reach their potential."