Until 18 months ago, Jane Cunliffe was, she says, a “dyed-in-the-wool civil servant”.

At that time, she had spent nearly two decades in a series of powerful jobs in Whitehall. She started as a policy wonk at the Department for Education, before moving to a finance role at the same department. Then she helped run Nick Clegg’s private office during the coalition years (this was “a weird and wonderful job”, Cunliffe says), before a stint as director of public spending at the Treasury and then in a senior position at the Department for Work and Pensions.