A former Treasury aide marched out of Downing Street by armed police after being sacked by Dominic Cummings has said she was “never given a reason” for her dismissal.

Sonia Khan, who was fired as a special adviser to then chancellor Sajid Javid in August 2019 over the alleged leaking of Brexit secrets, said she took legal action against the Government to stop it happening to others.

During an angry confrontation in No 10, Mr Cummings was reported to have accused her of being in contact with allies of her former boss, Philip Hammond, who was chancellor under Theresa May – claims she denied.

She subsequently announced she was taking the Government to an employment tribunal, claiming unfair dismissal and sex discrimination. The Government agreed to settle the case at the end of last year.

In an interview with BBC Radio 4’s Woman’s Hour, Ms Khan said she was never told what she had allegedly done wrong.

“I was called in for a meeting that I wasn’t expecting, and then I think much of that has been reported in the media rightly or wrongly, so I don’t want to get sort of too into that.

“But I think the main thing to point out on my end was that I was never given a reason about why what happened happened, and that for me was the sort of trigger to take the action that I did, which is the legal action that I’m referring to today.

“Nobody ever said it was because you did X, Y or Z – I know there were lots of reports in the media but none of that was ever put to me.

“I remember at that time feeling quite strongly that if I’m not given a reason and if there’s a chance that this can happen again, it sets a really bad standard and a precedent.

“Especially for a lot of the advisers who were coming into that Government who were really young at the time, like early twenties, so I felt like I had a real responsibility to them.”

She said she felt a “sadness” when she processed the events, but dismissed as untrue the allegations that were levelled at the time.

“For me, being someone who comes from a very working class background, it’s a hugely privileged role, so the idea that when you fought so hard to get a seat at the table you would then give that up to leak something or have improper relationships isn’t true,” she said.

Ms Khan also said the police officer who walked her out of Downing Street appeared “shocked” at the request to escort her because he “hadn’t been in that situation before”.

She said: “My first thought was I really feel sorry for this man because he’s now going to have to write this up and go through a proper process.

“And actually since then I had a really good conversation with the Metropolitan Police who assured me that they now have processes in place to make sure that that doesn’t happen again and so no-one feels compromised.”