One of the UK’s top employment experts believes the young aide sacked by Dominic Cummings may have been unfairly dismissed from her job.

Sonia Khan, a Treasury media adviser, was escorted by armed police from Downing Street after a confrontation with No 10’s chief strategist over her contact with those close to the former chancellor Philip Hammond.

She was accused of lying about her conversations with Hammond’s former staff member Poppy Trowbridge by Cummings, who is understood to have found evidence they had been in touch on her personal mobile phone.

John Bowers QC, a leading employment barrister, said: “If she did lie then clearly there would be a basis for dismissal but it doesn’t look as though any proper procedure was adopted and HR wasn’t present.

“She wasn’t given the right to be represented and being bundled off the premises by police is completely humiliating so I think it would be unfair dismissal.”

Cummings was said to be unrepentant about his high-profile sacking of the 27-year-old Khan, who had been working for the current chancellor, Sajid Javid, and before that for Hammond as an adviser.

In a meeting on Friday night with Boris Johnson’s team of special advisers – known as spads – Cummings is said to have remarked: “If you don’t like how I run things, there’s the door.”

There is no indication Khan is planning on taking any legal action against the government over her sacking.

Despite several requests for an investigation into Cummings’ behaviour by the government’s head of propriety and ethics, Helen McNamara, no inquiry is currently taking place although she has spoken to Khan about the incident.

Although she worked for the chancellor, spads such as Khan are held ultimately responsible to the prime minister’s office. Javid confronted Boris Johnson in a heated discussion about why his staff member had been fired without his knowledge.

Yvette Cooper, the Labour chair of the Commons home affairs select committee, said: “Government advisers must not abuse their power by drawing the police into heavy-handed political stunts. This needs to be reviewed by the cabinet secretary and the Metropolitan police straight away.”

Bowers added: “She should have been given warning of what the meeting was about. It may be that they needn’t have told her what evidence they had against her, but the nature of the meeting and fact that it could lead to dismissal, she should have been told about that.”

He said the humiliation of her being marched out of No 10 would aggravate the element of unfairness in what happened to her and a tribunal judge “would hate that”.

Unfair dismissal cases can only be brought if someone has worked for an organisation for more than two years, unless it is a case of discrimination or whistleblowing.

Khan began working for the civil service in 2014 and became an adviser in 2018. It is not known whether she has unbroken service.

There was outrage surrounding Cummings’ move to fire Khan last Thursday, with No 10 described as operating amid a “climate of fear”.

The prime minister also faces being summoned to the Commons on Monday to answer an urgent question on the handling of the case.