Early election rumours are again rippling through Westminster. The truth is, of course, that no general election can be called during recess without a recall of parliament. There is no motivation for the prime minister to take such a step, not while the novelty of that title still chirrups in Boris Johnson’s own ears and tolls in those of his foes. But after recess, all bets are off. Johnson’s announcement on Sunday of a £1.8bn cash bonus for the NHS was a pre-election cookie if ever we saw one.

Where Labour moderates lead, Tory waverers may take longer to follow

Take your pick of the Merovingian mechanics by which we get there – a no-confidence vote, parliament blocking no deal – an election is coming. Yet for at least 20 moderate Labour MPs, and a fair few Tory ones, an internal struggle is being fought: can they knock on doors and honestly ask voters to endorse the leader of their own party? The idea of a choice between Johnson and Jeremy Corbyn fills many voters with horror. But more importantly, it fills the parties’ own MPs with dread too.

Rumours have circulated for some time now of alternative new parties, of moderate electoral pacts. Every week, it seems, a chunk of the Labour parliamentary party change their minds about how they’re going to avoid campaigning for Corbyn at the next election. From now until the Labour party conference, they will distractedly expend their energies avoiding deselection. They are wasting their efforts. And they are wasting the country’s time. The window to jump ship – whether to the resurgent Liberal Democrats, to a new centre party, or to some electoral combination of the two – is closing rapidly.

Corbyn is not going to be ousted as leader of the Labour party before 31 October; Momentum and Unite are not going to suddenly lose hold of the factional national executive committee (NEC); Tom Watson, wounded by his support for the fantasist Carl Beech, is not going to be in a position to wrest control of the Labour party. Corbyn’s outriders may worry about a media smear campaign against their man, but they can rest assured that no newspaper editor is likely to throw their weight behind Watson, a man defined on Fleet Street by his lifelong crusade to impose content regulation on the press.

It’s hard to leave a party in Britain, let alone found a new one. Those of us who burned political relationships to speak about sexual harassment in Westminster know that better than anyone. But sometimes, it’s necessary. Change UK jumped too soon, and the social democratic cavalry failed to ride in to their rescue – but there was something joyous in seeing MPs such as Heidi Allen and Luciana Berger liberated to speak their minds about their former bosses. Privately, senior staffers around both leaderships speak of their amazement that moderate MPs have waited this long to split. The hard left’s Praetorian guard mocks moderate Labour much as the Tory hard right mocks its moderates: as “wet” in both content and character. Until moderates finally show some mettle, they will deserve it.

Where Labour moderates lead, Tory waverers may take longer to follow. The reconfiguration in British politics goes far deeper than Brexit – and any new party would be foolish to brand itself as a continuity remain organisation, as Change UK did to its fatal cost. But dissident Tories will have more political cover to take a stand if and when Johnson finally declares for a no-deal Brexit. Plenty are already indicating their horror at a Johnson-Corbyn world. Phillip Lee, a man of great principle but traditionally wet vacillation, has announced he will take the summer to consider whether to join the Lib Dems; a move which would wipe out Johnson’s majority.

By the end of the summer, however, it will be too late for Lee and it will be too late for Labour’s dissidents. No one can run a general election campaign without knowing three months before polling day which rosette they’ll be wearing. It’s make-up-your-mind time, folks.

• Kate Maltby writes about theatre, politics and culture