To properly understand the crisis that has detonated beneath Keir Starmer’s government with the firing of Peter Mandelson, you first have to understand this. It isn’t actually Keir Starmer’s government at all. Look around his administration and you will notice a common thread running through it. One that leads all the way back to Tony Blair and the New Labour administration of 1997.

First, there is Mandelson himself. The common perception is he returned from the political wilderness last December to become Starmer’s man in Washington. But in reality, he was already exerting his Machiavellian – his critics would say malign – influence via his close friendship with Starmer’s senior aide Morgan McSweeney. ‘Morgan and Peter were in constant contact,’ a minister told me.

Officially Mandelson was ambassador to the US. But in truth he had control over huge swathes of British foreign policy. ‘Inside the Foreign Office people began to call Mandelson the real Foreign Secretary,’ one official recalled.

In fact, he nearly was Foreign Secretary. I’m told that prior to the election, serious consideration was given to formally appointing him to the role, in a parallel of Lord Cameron’s shock appointment by Rishi Sunak. But it was reportedly opposed by Sue Gray, Starmer’s then chief of staff, who had a number of concerns, including issues over security vetting.

As a result of which he had to content himself with again pulling the strings from behind the scenes. Though they were significant strings. On the day of Angela Rayner’s resignation, he was seen slipping into Downing Street. Officially, it was for a pre-arranged meeting to discuss Donald Trump’s state visit. But according to ministers, it was actually to assist McSweeney with the reshuffle.

So former senior Blairite adviser Peter Mandelson sat across British foreign policy. And to assist him, a month before his own appointment, former senior Blairite adviser Jonathan Powell was drafted in to take charge of the national security apparatus, replacing Sir Tim Barrow as National Security Adviser.

On the same day as Powell’s appointment, it was also revealed former senior Blairite adviser Liz Lloyd had been appointed to direct the development and implementation of the Government’s policy agenda.

And Lloyd was in good and familiar company. Because the day after the election it had been announced that former senior Blairite adviser Pat McFadden had been placed in charge of the Cabinet Office, responsible for aligning the Government’s political and delivery strategy.

‘The three most important people in the Government are Morgan McSweeney, Rachel Reeves and Pat McFadden,’ a minister told me. ‘After Keir Starmer?’ I enquired. ‘No,’ they replied.

And that isn’t the end of it. Two weeks ago it was announced former senior Blairite adviser Tim Allan had been drafted in to take up the role of Downing Street director of communications. It also emerged that close friend and ally of Peter Mandelson, Peter Kyle, had just been given the role of Business Secretary. Meanwhile, another close ally and friend of Mandelson, Wes Streeting, was being installed as the bookies’ favourite to replace Starmer as next Labour leader following Rayner’s departure.

You can see the pattern here. Under Keir Starmer’s putative premiership, former senior advisers to Tony Blair have been placed in charge of British foreign policy, Britain’s national security apparatus, Britain’s national policy development and implementation, the management of Britain’s political and delivery strategy, and the direction of the British Government’s communications strategy. By proxy, former senior advisers to Tony Blair have also been placed in charge of Britain’s global business strategy, the nation’s health policy, and are being lined up as a likely replacement for Keir Starmer as Prime Minister. Oh, and Tony Blair’s former fundraiser Lord Alli – also a good friend of Peter Mandelson – has been running around buying the Prime Minister’s suits.

Over the past few days, ministers and MPs have been watching with increasing bemusement and horror at Starmer’s attempts to lash himself to Mandelson, even though it was becoming clear to everyone with half a political brain cell he would have to go. ‘How can he not see how disastrous this is?’ said one despairing minister.

But Keir Starmer could see. The problem was, his entire government had basically become a giant Blairite Jenga Tower. And by pulling out and discarding the brick that was Mandelson, he risked bringing the whole facade crashing down around him.

As he still might. This weekend the Prime Minister is waiting in trepidation to see if Mandelson will wreak revenge for his sacking. ‘The fear is Peter has decided to take Keir down with him,’ one official told me. So how has Starmer got himself into this mess? Why did a man who didn’t really have ideological synergy with the Blairites sub-contract his own political project to them?

Partly it’s because he has very few allies in government. And those who were with him at the start of his political journey – such as his first Shadow Chancellor, Anneliese Dodds – have quickly fallen by the wayside.

Another explanation is that for all their faults – and Peter Mandelson has had enough for three full-blown scandals all of his own – the Blairites provided the hands-on experience that Starmer and other members of his team were lacking. Though the boast ‘the grown-ups are back in charge’ now looks laughably – or tragically – misjudged. But the main reason is that Keir Starmer simply has no coherent vision or strategy.

As the first tortuous year of government has brutally exposed, the Ming vase he carefully curated during his journey into government was empty. There is nothing there. Starmer literally has no idea what he wants to do with power, save for keeping it out of the hands of Nigel Farage and Kemi Badenoch. So it’s really no wonder he fell under Peter Mandelson’s seductive spell.

Soon after Starmer was elected, Mandelson was telling friends he believed Labour’s new leader had ‘come badly unstuck’. But as the polls started to turn, Mandelson again began demonstrating the knack for aligning himself with wealth and power that would ultimately prove his downfall.

Even though they were not close socially, in 2023 Starmer was one of only a small number of serving politicians to attend Mandelson’s wedding. And by the time Labour entered power, Mandelson had again manoeuvred himself into a position where he was a senior – if discreet – member of the Labour inner circle. With the disastrous results everyone can now see.

There is now speculation the Mandelson affair could prove a crisis too far for Starmer. The deputy leadership election triggered by Rayner’s resignation has become a de-facto referendum on his premiership.

The scandal has driven a wedge between the Prime Minister and McSweeney. And questions remain about the vetting process surrounding Mandelson’s appointment, and why the full nature of his relationship with Epstein was not revealed.

But those looking on with bemusement at the implosion of Keir Starmer’s government are missing the point. It has never really been his government. And now it probably never will be.