Internally, Boris Johnson has given short shrift to those who have suggested that he distance himself from the Home Secretary. There is a view in Downing Street that several of the most dramatic charges against her don’t stack up.

Number 10 knows, though, that it has a fight on its hands to save Patel. One source tells me, ‘Yes, she can survive. But there’s no smoke without fire. It is shaping up to be quiet a big struggle’.

Part of the issue is that there is a view among senior civil servants that because the top civil servant at the Home Office has quit because of this row, Patel should go too.

But Downing Street know that if Patel goes, it would become harder to push reform through the system. One of those at the heart of government tells me, ‘You can’t have a situation where civil servants get to determine who their Secretary of State is’.

The next hurdle for Patel to clear is Sir Alex Allan’s inquiry into whether her behaviour breached the ministerial code. There is a quiet confidence among her allies that while she’ll receive some criticism from his report, she won’t be found guilty of breaching the code.

But if her former Permanent Secretary Sir Philip Rutnam really is determined to take his case to an employment tribunal then the situation will become far more difficult for the Home Secretary.