“Unity” was Jeremy Corbyn’s watchword after his re-election. His reshuffle demonstrated that it will be on his terms. The third of his leadership was his most decisive to date. The long-serving Rosie Winterton was sacked as chief whip (to the consternation of MPs), close ally Diane Abbott was promoted to shadow home secretary, shadow defence secretary Clive Lewis was moved to business (after a conference spat over Trident renewal) and Shami Chakrabarti was made shadow attorney general (as I anticipated last week).

Corbyn’s allies described the appointments as evidence of his increased confidence. “It’s a butterfly from the chrysalis moment,” a shadow cabinet minister told me. Despite Corbyn’s absence from Westminster (he was in Glasgow to deliver the Jimmy Reid Lecture), the reshuffle was efficiently conducted. The Labour leader's strategy and communications director, Seumas Milne, was central to the changes and, having been expected to depart, was tipped by some to now remain.

The moves began when Winterton, chief whip since 2010, saw Corbyn for a pre-scheduled meeting on the possible return of shadow cabinet elections. But rather than negotiating with the Doncaster Central MP, Corbyn sacked her. Allies had been demanding the removal of Winterton since last year, charging her with disloyalty during the Syria vote.

The move was immediately condemned by Labour MPs. “Sacking the unifying chief whip shows ‘reaching out’ meant nothing,” tweeted Neil Coyle. “Clear Corbyn wants submission not unity. Ignoring wishes of the PLP and just sacking and appointing regardless,” wrote Tom Blenkinsop. An MP warned that members of Winterton’s “fiercely loyal” team could resign in protest.

There was further shock when her replacement was announced as Nick Brown. Securing the veteran Newcastle MP, who served as chief whip from 1997-98 and from 2008-2010, was a coup for Corbyn. Just as Ed Miliband sacked Brown to demonstrate his authority, so the Labour leader reappointed him to assert his. A shadow cabinet minister described the move as “inspired”, suggesting it would encourage a broader range of MPs to return. But others said some were “wobbling” after Winterton’s sacking.

This move was followed by the appointment of Abbott as shadow home secretary. The Hackney North MP is a friend of decades’ standing and shares Corbyn’s liberal stance on immigration. For the first time, as the Labour leader proudly noted, two of the great offices of state are now shadowed by women.

Her appointment, however, also means that the four most senior posts (leader, shadow chancellor, shadow home secretary and shadow foreign secretary) are exclusively held by London MPs. In addition, Keir Starmer, the highly-rated Holborn and St Pancras MP and former director of public prosecutions, was made shadow Brexit secretary.

“It’s like getting six numbers on the Lottery for the Conservatives,” said a Corbyn critic in reference to Theresa May’s conference speech, hailed by the press as an attack on the “metropolitan elite”.

But having been condemned for an initial lack of female appointments during Corbyn’s first reshuffle, his team learned their lesson, announcing three others alongside Abbott. Recently-appointed peer Chakrabarti was made shadow attorney general, Sarah Champion became shadow women and equalities minister and Jo Stevens was named shadow Wales secretary. Despite a number of former frontbenchers, such as Heidi Alexander, Kate Green and Kerry McCarthy, refusing to return, sources say the shadow cabinet will remain majority female.

Another positive headline was provided exactly an hour later with the appointment of Brent Central MP Dawn Butler as shadow minister for black and minority ethnic communities. “I am very proud that the Labour Party now has five MPs in our shadow cabinet from the BAME community – the highest number ever in any cabinet or shadow cabinet,” Corbyn announced.

An hour after this, to counter criticism of a London-centric team, Labour confirmed the appointment of Jonathan Reynolds as shadow economic secretary, one of 10 northern MPs to have joined the frontbench.

The final appointments of the evening saw Starmer made shadow Brexit secretary, Lewis moved from defence to business and Jon Trickett retained as shadow lord president of the council and Labour’s national campaigns co-ordinator. (More changes will follow tomorrow, with Rachael Maskell tipped by sources to become shadow health secretary and John Healey expected to return.)

It was Lewis’s new role that prompted most reaction. The former shadow defence secretary was recently enraged when a line stating that the party would maintain its support for Trident renewal was removed from his conference speech. He was replaced by the unilateralist Nia Griffith (another assertion of Corbyn’s authority). But a shadow cabinet minister said Lewis was pleased to have won the business brief, regarded as pivotal to Labour’s “21st century socialism”.

Though Corbyn’s reshuffle is being described as “ruthless” it is no more so than those of previous leaders. The difference is that his predecessors enjoyed far greater support among the parliamentary party. As few as 15 of Corbyn’s colleagues voted for him.

The return of shadow cabinet elections will be discussed at an NEC away day in November but the reshuffle has further alienated some MPs. “Classic strategic overstretch,” said one. “Corbyn, in one stupid, arrogant and deeply incompetent move, has shattered the pretence of unity, squandered his honeymoon as a re-elected leader and made a load of new enemies.”

But having achieved two landslide victories in a year, the Labour leader has demonstrated that he is determined to hold power, rather than merely office.