London has the largest gender pay gap in the UK, according to new figures released by the Office for National Statistics (ONS) on Monday (27 November).

Two decades ago, the capital had one of the smallest gender pay gaps in the country, with women earning on average 15.1% less per hour than their male counterparts.

However, over 20 years, the gap has only narrowed to 14.6%, while the national rate fell to a historic level of 9.1% in April.

In Wales the gap has fallen from 17.5% in 1997 to 6.3% this year and in Scotland it has narrowed from 18.4% to 6.6%.

In Northern Ireland, meanwhile, women earn on average 3.4% more than men, the only UK region where the pay gap has been favouring women, a trend which has not changed since it first emerged in 2010.

"London is now the region with the biggest pay gap, on average, between male and female full-time workers in the UK," the ONS stated.

The data also showed that among part-time workers women were likely to earn more than men, partially because of the higher number of women working part-time, compared to men. Men's wages, however, have grown faster than women's among those who do not work five days a week and the 9% gap recorded 20 years ago has significantly narrowed.

The gap within part-time workers is at its smallest in the south east of England, where women earn on average 3.1% per hour more than their male counterparts.

However, the pay gap among part-time workers in the public sector has widened, with women's hourly wages on average 22.3% smaller than men's, compared with a 6.1% gap in 1997. Conversely, among private sector employees, women earn 2.6% more than men among part-time workers, while in 1997 women's hourly wages were 2.2% lower than men's.

In April last year, in a bid to address pay disparity, the government introduced legislation requiring any UK business with at least 250 employees to publish data on the difference between how much they pay men and women at different levels within 12 months.

However, the move attracted criticism, with some industry experts suggesting disclosing the pay gap will not be enough to tackle the issue.