The gender pay gap has barely changed over the past four years, the Office for National Statistics (ONS).

The ONS said the gap fell just 0.2 percentage points 9.6% in 2014 to 9.4% in 2015. It was the narrowest gap since record began in 1997, but the gap has remained at around £100 per week for much of that period, particularly in the past four years.

According to the figures, men now earn an average £567 per week, while women earn just £471 per week. However, among part-time workers, women actually earn more, up from 5.5% last year to 6.5% this year.

The Trades Union Congress (TUC) said that based on these latest figures, it could be another 50 years before the full-time gap is closed.

"Progress on closing the full-time gender pay gap has slowed dramatically over the last few years," said TUC general secretary Frances O'Grady.

"If it continues to fall at this pace, we're looking at nearly half a century before we have pay parity between women and men."

New legislation will require businesses that employ more than 250 people in England, Scotland and Wales will be required to publish the average wage for both genders.