For a man often said to be a people pleaser and conflict avoider, in his two years as prime minister Boris Johnson has sacked 27 cabinet ministers. His three reshuffles so far have been brutal, rejecting any attempt at a broad church.

Whitehall sources said the casualties were intended to put his ministers on notice about the prime minister’s strength of position. Robert Buckland, the justice secretary, lost his job despite no discernible wrongdoing. Gavin Williamson, the education secretary, was unceremoniously fired despite fears be could be a threat on the backbenches. One government source said all ministers “would know they are dispensable”.

One Tory compared the reshuffle to Margaret Thatcher’s 1981 “purge of the wets” – a brutal show of authority after 18 months of rebellions and U-turns. “Boris has shown people he’s in charge,” they said. “People won’t mess around now though. Anyone can get chopped.”

A senior aide said the prime motivator for the changes was the qualities Johnson prized most highly: loyalty and delivery. “That’s what the promotions are intended to show – that’s encapsulated in [the new culture secretary] Nadine Dorries, incredibly loyal, and in [the new education secretary] Nadhim Zahawi, incredible delivery.”

But one former Conservative cabinet minister called Johnson’s new top team “a cabinet of short poppies”, saying he does not like to be surrounded by potential rivals. “Who are the big beasts?” they asked, claiming the prime minister could have brought back heavy-hitters such as Jeremy Hunt.

Tory MPs from former Labour “red wall” seats are also wondering what message the reshuffle sends to their voters. Despite promises from a No 10 source that there would be a “focus on uniting and levelling up the whole country” there is little new geographic diversity in the cabinet. “Tell me one cabinet minister who understands my voters,” a northern Tory complained.

Late in the evening, Johnson answered that question by promoting one of his most loyal red wallers, Simon Clarke, MP for Middlesbrough South and East Cleveland, to chief secretary of the Treasury – perhaps a signal to the chancellor Rishi Sunak of his future spending priorities.

The sackings were intended to be done swiftly after prime minister’s questions on Wednesday lunchtime. But no matter how many times Post-Its are moved around a whiteboard in Downing Street, there is always a a cabinet minister who can kick up a stink and make the unexpected happen.

In the prime minister’s office in parliament, tucked behind the Speaker’s chair, Dominic Raab point blank refused a straight demotion from the Foreign Office to the Ministry of Justice despite coming under fire for the chaotic withdrawal from Afghanistan last month.

During a tense negotiation, Raab extracted the title of deputy prime minister – a job that did not exist in Johnson’s cabinet, though Raab had often been described as de facto deputy, and one that will arguably give him more right to attend vital strategy meetings.

One source close to Raab claimed it as a victory, saying “he’s the Rayner of the reshuffle” in a comparison with Keir Starmer’s botched demotion of his deputy Angela Rayner, where she emerged with a more powerful role. Another of Raab’s allies dismissed that idea. “It took Angela Rayner all day – Dom did it in 45 minutes.”

It is hard to argue, however, that a move to become justice secretary is not a demotion. Raab left parliament on Wednesday afternoon with his future still uncertain before negotiations moved to Downing Street where his new title and department were confirmed. As he headed to the Ministry of Justice in Victoria, his team left to pick up the pieces of a planned US trip next week which Raab would now not be attending.

Though his departure had been widely briefed, sources close to Raab believed he could survive the damaging stories about his absence on holiday during the Afghanistan withdrawal.

“He’s been treated abysmally,” one MP close to Raab fumed, recalling how the de factor deputy prime minister took charge when Johnson was in intensive care with Covid last year. “This is the man who stepped up as the PM was dying, he ran the country and he never used it to burnish his own image. He’s been loyal to a fault, it’s outrageous.”

Of the sacked ministers, it was Buckland – Raab’s predecessor as justice secretary – for whom ministers voiced the greatest sympathy. “What has he done wrong in the last two years? Nothing,” one said. Another said he was “very competent and popular and will be missed”.

Few MPs had any sympathy for Gavin Williamson, who is said to have given an early leaving speech to his department on Wednesday, so certain was he that his fate was sealed. Sources said he had asked in previous months to be given the job of chief whip or leader of the House. Johnson did not seem to think it necessary.

“Gav’s always seen as this big organiser of MPs but I think his star has diminished too much to be any kind of real threat,” a former minister said. Another minister said Williamson’s removal came “two years too late”.

The appointment of Liz Truss to the Foreign Office will delight many of the party faithful – some MPs had wondered aloud if Johnson would really promote a minister more popular than himself. But it has dismayed many soft Tories who see it as another sign that the UK’s foreign policy ambitions are diminishing.

“Surely there must be a limit to how far Truss can be over-promoted?” one senior MP grumbled. Another said: “Our wing of the party has suffered quite a few indignities over the past two years but every time you wonder how bad things can really get, you find Liz Truss in the Foreign Office and Nadine Dorries in the cabinet too.”

As well as Priti Patel keeping her post as home secretary, there is one great winner of the reshuffle – Sunak. Cabinet ministers have only just delivered their submissions arguing for funding the spending review next month.

Now new cabinet ministers will be awkwardly bound by their predecessors, and unable to marshal any significant change of direction. As ministers start to grapple with their new briefs, many decisions will already be out of their hands. “It’s the first rule of government: the Treasury always wins,” a senior aide joked.