Priti Patel may have to give evidence at an employment tribunal over claims she forced out the Home Office’s most senior civil servant.

The Home Secretary has been accused of bullying staff and allowing a press briefing campaign against Sir Philip Rutnam, who resigned as the department’s permanent secretary in February.

Sir Philip is bringing a claim for constructive dismissal against the Home Office. He has named Ms Patel personally as a respondent, according to the Guardian, which raises the prospect she may be called as a witness when the case is heard in a tribunal next September.

It is likely that the Government will try to resist the prospect of the minister taking the witness stand in the 10-day hearing. No secretary of state has ever been taken to an employment tribunal by such a senior mandarin before.

Bullying claims

Sir Philip is pursuing his claim under whistleblowing laws which mean that there is no theoretical limit on the payout he could receive if he is successful.

When he resigned, he said in a televised statement: “I have been the target of a vicious and orchestrated briefing campaign. It has been alleged that I have briefed the media against the Home Secretary. This – along with many other claims – is completely false.”

Ms Patel was guilty of “shouting and swearing, belittling people, making unreasonable and repeated demands – behaviour that created fear and that needed some bravery to call out”, Sir Philip claimed. He said other civil servants had repeatedly complained about the secretary of state.

The allegations triggered a Cabinet Office investigation into the Home Secretary, which has still not reported back seven months later. Despite media claims that the inquiry clears her of serious wrongdoing, Ms Patel says she has not seen a copy of the final report.

Allies of the Home Secretary insist that she is the victim of an orchestrated campaign by civil servants who are opposed to her because of her stridently pro-Brexit views and plans to reduce immigration. Over the weekend she announced new plans for a two-tier asylum system with those who reach Britain by illegally crossing the Channel put at the back of the queue.

Sir Philip was the first of a series of permanent secretaries who have left their post this year as the Government carries out reform of the civil service driven by Boris Johnson’s chief aide Dominic Cummings. Several others are said to have fallen out with ministers but none has gone public in the same way.