Priti Patel had to personally approve a program to relocate some asylum seekers from the UK to Rwanda, after her officials expressed concerns about value for money.

The home secretary gave an uncommon “ministerial direction” to push the plans through, implying that she is personally responsible for them.

The Home Office has only exercised the power twice in the last 30 years.

The idea was “divisive,” according to a top public employees’ union, but staff would have to adopt it or resign.

“Civil employees know their responsibility is to serve the government of the day,” FDA general secretary Dave Penman told BBC News.

They sign up knowing that they may not agree with the government’s actions.

“On the more divisive policies, which this clearly is, they face a choice – implement or leave. That could mean elsewhere in the Home Office, another department, or the service.”

Mark Serwotka, general secretary of the Public and Commercial Services (PCS) Union, said: “For the government to attempt to claim this is anything other than utterly inhumane is sheer hypocrisy.”

He added, “We have already seen that they are prepared to risk lives by turning boats back in the channel – a policy which we have had to take them to court over.”

“It is a heartless approach that displays total disregard for human life which everyone must oppose.”