Barclays International has a "shocking" gender pay gap, according to the chairman of the Treasury select committee.
Nicky Morgan MP said the gap, of 43.5 per cent, needed to be addressed.
She said: "On average, women at Barclays International are paid half as much as men. For this to be the case in 2018 is shocking.
"Barclays released the figures at the same time as its results, which were disappointing."
Under new legislation, companies with more than 250 employees must report their gender pay gap on a website before April 2018.
Analysis of the figures shows that only 28 of the 1,154 companies that have reported their gender pay figures have a higher median hourly pay gap than Barclays.
Ms Morgan said: "Barclays has signed up to the Women in Finance Charter, which commits signatories to supporting the progression of women into senior roles in the financial services sector.
"One way of reducing the gender pay gap is to increase the proportion of women in more senior roles, so it appears that Barclays is on the right track.
"As part of our Women in Finance inquiry, we will keep a close eye on organisations as they report their gender pay gap before the April 2018 deadline.
"We may call for organisations to give evidence to the committee to hear about best practice. Financial firms should be prepared to explain any gender pay gap that they may have."
Barclays International is the investing arm of Barclays Bank.
The UK retail bank has a smaller gender pay gap, with women earning 14.2 per cent less than men on average, while the figure is 29.9 per cent for the holding company, Barclays Services.
The gap in investment banking is exacerbated by the small number of women in senior positions
There is only one woman on Barclays's nine-member group executive committee, Laura Padovani, who is the firm's interim chief compliance officer.
Barclays has been contacted for comment by FTAdviser.