Senior ministers and assistants entered the work from North 10 number

A senior civil servant familiar with the discussion said that those who were on leave were told that their plans would be carried out when they returned.

Dave Penman, general secretary of the FDA union, which represents senior civil servants, welcomed the changes to the government structure and warned that relocating would be a big decision for workers.

“People who are thinking of leaving London are concerned that it will be difficult to return given the difference in house prices,” he said, adding that the main focus was “whether it looks like a permanent reshuffle or something that could change quickly with a future government”.

Burnham told cabinet members No 10 North was not a mass to appease critics – and civil servants whose jobs could be fixed by the plan – still needed to prove it could make a lasting difference.

Dr Simon Kay, author of the Re:State report, which Burnham was involved in when he was mayor of Greater Manchester, told the BBC that 10 North should have been bigger than Burnham’s administration.

“That means reaching a critical mass, creating a real sense of common purpose and getting to a place where 10 North feels sufficiently distinct and important that whoever becomes the prime minister can continue,” he said.

While most civil service workers the BBC spoke to welcomed the idea of ​​Number 10 North, most ministers and political journalists, as well as many business leaders, continued to be based in London, while some doubted whether it would feel much different from regional government offices.

Some civil servants in the north of England believe they should be given the chance to apply for jobs at 10 North before talks begin on severance packages that could be lucrative for workers moving from London.

One official, who spoke on condition of anonymity because of civil service laws, told the BBC: “I’ve built my career here and I’ve seen first-hand that the north is a home for exceptional talent.”

“No 10 North should make the best use of all talent and create opportunities for people to build careers that are close to the communities they serve.”

Henry Morrison, chief executive of the Northern Powerhouse Partnership, said the government had been moving civil servants out of London over the past several years, including to the new Darlington Economics Campus: “A lot of civil servants are based here but rarely ministers”.