Allegations which led to Tory leadership hopeful Dominic Raab signing a non-disclosure agreement (NDA) were brought “vexatiously”, one of his supporters has said.

Maria Miller, who chairs the Commons Women and Equalities Committee, said the former Brexit secretary had signed the NDA to allow a case to be settled.

Mr Raab has previously said he was subject to a claim of bullying in 2007 – before he became an MP – and was party to a non-disclosure agreement.

Mrs Miller’s committee criticised employers who “routinely” use NDAs to cover up allegations of unlawful discrimination and harassment in the workplace in a report published on Tuesday.

She told BBC Radio 4’s Today programme: “I think Dominic Raab’s case is an excellent example of where people can be forced into signing NDAs when they don’t particularly want to do that.

“It was used to try to allow the case to be settled as opposed to a thorough investigation and as it was shown Dominic Raab there were no issues there at all and the case had been brought vexatiously.”

Parliamentarians launched an inquiry in November because of concerns about the use of NDAs, following an earlier report on sexual harassment in the workplace.

Following the committee’s latest probe, MPs are calling on the Government to “reset the parameters” within which NDAs can be used, and to fix the “failure” of the employment tribunal system to provide employees with “a meaningful route of legal redress”.

Mrs Miller told Today that NDAs should eventually be stopped altogether.

“We do believe right now we need the Government to reset the parameters, but there should be a direction of travel towards stopping them being used altogether.

“It is possible and at the moment they are being used as legally sanctioned secrecy, particularly around discrimination cases of all different types.”

Topshop boss Sir Philip Green took out a legal injunction preventing The Daily Telegraph from publishing allegations of sexual harassment and racial abuse.

It was revealed by the newspaper that five employees had signed NDAs to keep their complaints confidential after the Arcadia owner’s High Court action ended.

Sir Philip denied that his alleged behaviour was criminal or amounted to gross misconduct.

The Women and Equalities Committee’s report, published on Tuesday, said: “The difficulties of pursuing a case at employment tribunal, and the substantial imbalance of power between employers and employees, mean that employees can feel they have little choice but to reach a settlement that prohibits them speaking out.

“Our report shows unequivocally that in many cases signing a non-disclosure agreement is not benign.”

MPs said they received “shocking evidence” of the impact of NDAs on the lives of “ordinary people”.

The report added: “Some suffer emotional and psychological damage as a result of their experiences, which can affect their ability to work again or to move on.

“Some also suffer financially as a result of losing their job and bringing a case against their employer.”

The committee warned that victims may be reluctant to report allegations of discrimination for fear they would not be taken seriously under a “cover-up culture”.

“Insufficient focus and force from regulators to require employers to do more to protect employees has to change,” the MPs’ report said.

“It is in the public interest that employers tackle discrimination and harassment and that allegations of such behaviour are investigated properly and not covered up by legally sanctioned secrecy.”