So deeply did Tony Blair loathe being leader of the Opposition that he pointedly declined to decorate or otherwise personalise his parliamentary offices between 1994 and 1997. Every fibre of his being was strained towards the acquisition and retention of power — on the basis that to behave otherwise would be an unconscionable betrayal of t hose whom Labour was founded to protect.

Compare and contrast Jeremy Corbyn, whose first conference speech as Labour leader barely mentioned the general election result or the epic scale of what the party must do if it is to win again. Pressed to explain Ed Miliband’s defeat in May, those around Corbyn revert to the old refrain of the Left: that the party’s message was insufficiently “clear” and that, in this case, an unambiguous anti-austerity strategy would have swept all before it in the election.

That is, at best, a rickety thesis. Yet the more profound question is whether Corbyn cares about power with the relentless fury that animated Blair and Gordon Brown.

In 13 years of Opposition, the Tories looked back on the Thatcher era as a golden age to be resumed — a restorationist dream that was also a politically costly delusion. But Labour has precisely the opposite problem. The party’s relationship with its New Labour past is akin to post-traumatic stress disorder. Here in Brighton, Blair is the pantomime villain and his years in office are recalled as at best a wasted opportunity and — more widely — a shameful chapter in the party’s history. That Labour should treat its most electorally successful leader with such contempt is patently absurd. But it is also the heart of the matter.

Like a doctor in the Wild West, Corbyn offers a remedy to all known forms of Blairism. His speech had little to offer the wavering voters that Labour must win over by the thousand to stand a chance of victory in 2020. But that was because his sights were set on a very different objective: not a Commons majority but a campaigning socialist movement harrying and haranguing the wicked Establishment.

“Just because I’ve become the leader of this party,” Corbyn said, “I’m not going to stop … being that activist.” His ideal Labour Party sounds less like a government-in-waiting than a nationwide pressure group that happens to have a parliamentary wing. The statistics that command his interest are the number of new members he has attracted rather than his personal rating or the party’s standing in the polls.

"Corbyn’s ideal Labour Party sounds less like a government-in-waiting than a pressure group that happens to have a parliamentary wing" Matthew d'Ancona

The problem for Labour is that this is such an idiosyncratic perspective. Most voters want an opposition party that offers a coherent alternative with visible discipline. For those outside the movement, the passion of the rally or single-issue campaign is not enough, or even relevant. They will look instead at the reconstituted Labour Party and ask if it offers them anything more than slogans, petitions and T-shirts.

In Brighton we have been told by Corbyn and his principal sidekicks, John McDonnell, the shadow chancellor, and Angela Eagle, shadow first secretary of state and business secretary, to watch this space, to let the policy-making process run its consultative course, to have patience — and I suppose a party under new management gets to say that once with impunity. But once only.

In his speech Corbyn made light of the scrutiny to which he is now subject, but he had better get used to it. The most striking passage pivoted on his declaration that “you don’t have to take what you’re given”. These lines, it emerged, were written many years ago by former political adviser Richard Heller, and have been offered to every Labour leader since Neil Kinnock. Plagiarism? Not technically, perhaps, but certainly a lazy use of another’s words by a politician supposedly defined by his “authenticity”.

There are two ways to interpret the happy turmoil in Brighton: as the creative sinews of a reborn party flexing and stretching, or as the first tremors of imminent collective collapse. Ostensibly, the gathering has been a feelgood celebration of consensus and an end to 20 years of factionalism: not since the final scene of Bugsy Malone when the henchmen of Dandy Dan and Fat Sam join together in song has there been so much sudden harmony. But this is a truce for show, not a durable peace.

Even as the activists have celebrated the Dawn of the Era of Jeremy, they have kept half an eye on what comes next, should that era prove to be short and not especially sweet.

Tristram Hunt made many new friends at this conference. By electing the resolutely un-military Corbyn, the party has voted to give peace a chance. But if the experiment fails, it can always give war a chance too. Dan Jarvis, the former Para, burnished his credentials in Brighton as a warrior-leader-in-waiting. Meanwhile, the leading moderate, Rachel Reeves, spoke with as much panache and conviction as any Corbynista, reclaiming her position as a serious contender for the top job.

When might she and others find themselves in the running? It is commonplace to argue that Corbyn will be gone by Christmas, or after the May elections, or before next year’s conference in Liverpool. Yet Labour — unlike the Conservatives — is notoriously reluctant to remove its leaders.

To this generality add a further specific: that the Left is astonishingly good at stitching up procedures, internal party rules, and committee memberships. Corbyn, McDonnell et al have been quite explicit about their intention to rebuild the party from within. The moderates are holding fire while the new leader brandishes his mandate — his “Precious” — and waiting for him to stumble. But if they wait too long they may find that the party has been colonised by the Left, its bureaucracy transformed and its rules changed to ensure that the party is never again subjected to the nightmare of an election-winning moderate like Blair.

You see, it isn’t Britain that Corbyn wants to govern. It’s Labour.