Theresa May has finally begun to make headway on the long list of ministerial vacancies created after weeks of bruising Brexit votes. One name on the list of appointments is particularly striking: Seema Kennedy, the MP for South Ribble.

Kennedy isn’t the best known Tory to have been promoted this evening – that mantle goes to James Cleverly, who makes the move from deputy chairman of the Conservative Party to Dexeu. But the new junior health minister is certainly the most significant.

Since the messy aftermath of the 2017 election she has been at May’s side in the Commons, Downing Street and at meetings of Cabinet as her parliamentary private secretary and most trusted lieutenant. She is closer to May than almost anyone else and, unlike most of her inner circle, is near-universally respected by Conservative colleagues.

Mocking PPS resignations has, as Brexit takes a sledgehammer to the government payroll, become very easy sport for much of Westminster. But as much as the inhabitants of the roles are often little-known even within SW1, the work they do can make or break a Cabinet minister (for whom they serve as parliamentary eyes and ears).

That is especially true of the Prime Minister. Though she can still count on the services of Andrew Bowie, the well-regarded Scottish Tory MP who has served as her second PPS since late December, this of all weeks seems a strange time to voluntarily jettison an aide one colleague describes as "immense".

May does have form for this sort of move. Last June she appointed another No10 PPS, George Hollingbery, to a ministerial job at the Department for International Trade – a promotion that went down badly among Tory MPs who complained of her preference for loyalty over talent. Yet May’s promotion of Kennedy, described by another member of the government as "yet another inexplicably bad decision that leaves her weaker", makes very little sense if she believes she will be in Downing Street for much longer.

The obvious, inescapable truth is that May hasn’t much time left as Prime Minister. That, Tory MPs believe, explains this seeming act of political self-harm: May is using her power of patronage to give an ally a leg-up while she still can. "If you can’t help your PPS," one minister asks, "then what’s the point?"

Others concur. "It was either now or never for a government job, given how closely tied Seema is to this regime," says one Cabinet PPS. "Parachutes are provided for the loyal," says another. "Ladders are unavailable."

So while there is much wider discontent with other ministerial appointments tonight – particularly that of Will Quince, a Brexiteer who resigned as a PPS with a stinging attack on the government before the first meaningful vote, and Andrew Stephenson, the third-in-command at the Whips’ Office who colleagues suggest has been promoted in an act of cronyism – Kennedy’s appointment suggests that it might not be too long before there is a comprehensive clear-out under a new prime minister