Big name firms such as UBS, Vanguard, Invesco Perpetual, JP Morgan and Metro Bank are among those coming under scrutiny.

MP Nicky Morgan, chair of the Treasury Committee, has written to the 33 businesses regarding the fact they have yet to sign up to the charter, which is a commitment by the Treasury and firms to work together to build a more gender balanced and fair financial services industry.

The Treasury's Women in Finance Charter is a pledge for gender balance across financial services. As of November, the Charter had achieved over 160 signatories, representing over 600,000 employees in the industry, which is around 50 per cent of the total staff employed.

Among a number of commitments, the Charter requires firms to support the progression of women into senior roles in the financial services sector by focusing on the "executive pipeline and the mid-tier level and asks firms to firms to publicly report on progress to deliver against these targets.

The firms are:

Source: Treasury Select Committee

Mrs Morgan said the aim, "must be to see all firms in the financial sector sign up to the charter and make a concerted effort to improve their gender diversity, particularly in senior roles."

She said: "Huge multi-nationals including Goldman Sachs, JP Morgan and UBS are yet to sign up to the Charter, and if they don't intend to do so, the Treasury Committee wants them to explain why."