The Brexit fantasists may be beaten, but Brexit reality is a far tougher foe | Rafael Behr

Rishi Sunak didn’t choose an early July election so that defeat might spare him the hassle of hosting tomorrow’s summit of the European Political Community (EPC), but it is a duty he was glad to forgo.

Protocols of continental fellowship never came naturally to the Conservative leader and his party would have despised him for faking them. By contrast, Keir Starmer is grateful for the gathering in Blenheim as a chance to show how Britain under a Labour government is released from Brexit neurosis.

The EPC is not part of the EU. It was conceived by the French president, Emmanuel Macron, in 2022 after Russia’s invasion of Ukraine, as a way to include non-EU states in a wider circle of European solidarity. It is a talking shop, not a treaty organisation. The vague purpose and imprimatur of Macron’s vanity make it an object of scepticism in some Brussels corridors. As a launchpad for Starmer’s European policy “reset” , it is perfect.

The prime minister wants to project maximum good neighbourliness without sounding impatient to unpick the knotty details of Britain’s post-Brexit trade settlement – a negotiation for which there is no appetite in European capitals or EU institutions.

Starmer’s opening bid is something more amenable and available – a new UK-EU defence and security partnership , with security defined expansively to include energy supplies, climate policy and migration. That has the merit of offering Europe something it might actually want from Britain. It would restore the framework for broad strategic alignment envisaged in the “political declaration” that came attached to Theresa May’s Brexit deal and which was shredded by Boris Johnson.

As the only European country to rank alongside France as a serious military power, Britain has hardware and expertise to offer continental democracies that feel vulnerable to Russian aggression. That anxiety is soaring in proportion to shortening odds on Donald Trump returning to the White House in November, undermining Nato and appeasing the Kremlin .

Britain offering to deploy its security capabilities under a European banner will buy a lot of goodwill in Brussels. Whether that can be parlayed into favours on the trade side of the ledger is a different question. The official answer is no. The unofficial answer is not yet.

There was enough backchannel communication when Labour was in opposition for Starmer to know that his EU interlocutors will be grateful to no longer be dealing with Tories, but also that gratitude and good vibes don’t alter the calculus of economic interest. Johnson gave away so much commercial advantage in his haste to show that Brexit was “done” that Brussels has little incentive to tinker with the existing trade deal, even to satisfy Starmer’s relatively modest ambitions for closer regulatory alignment.

There are dozens of harder and more urgent problems consuming the technical and political bandwidth of the European Commission. There is also still wariness of making concessions that could be perceived as rewards for Britain’s decision to quit the club.

But there are things that the EU wants from the UK – fisheries access, a youth mobility scheme . Some continental governments are open to persuasion that reconciliation with London has benefits that should soften the usual Brussels allergy to anything that might enable economic competition from a non-member state.

The safe forecast is that relations will be better than they have been under the Tories and harder than pro-Europeans might have hoped. Johnson’s Brexit was designed to be irreversible. It is a ratchet of automatic divergence over time.

The eggs cannot simply be unscrambled. Creating something more palatable is a project requiring constant application of political capital, diplomatic energy and leadership. It isn’t something that can be cooked on a back burner or delegated too far down the ministerial chain. Yet Starmer’s priorities are elsewhere.

That could change if the Treasury runs out of ways to stimulate the economy without substantial easing of friction at the border with the single market. Business leaders, previously cowed by Conservative dogma, are enjoying their newfound liberty to lobby for closer EU ties .

Parliament has no shortage of Labour MPs poised to ask the prime minister if he will follow the economic facts when they point towards Europe. The Commons sect that cries heresy when any shadow of rationality passes across the sacred altar of Brexit is reduced in number and exiled to opposition.

To see the election result as a rebuke to their creed would overinterpret a more general rejection of incompetence and sleaze. Europe was absent from the campaign. But there is a causal link between the ideological mania that gripped the Tories in the aftermath of the Brexit referendum, the elevation of charlatans and mediocrities to positions of power, and the subsequent failure to govern well.

With Nigel Farage’s Reform party lurking in second place in dozens of Labour seats, Starmer will still be wary of anything that points towards restitution of open-border migration. But Reform voters are not all sovereignty cultists, ready to take up arms against a veterinary standards agreement if it acknowledges the jurisdiction of the European court.

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Starmer can start pushing the boundaries of European diplomacy deep into terrain that was off limits for a Conservative prime minister, and still be confident of occupying the mainstream centre-ground of British public opinion.

The era of Brexit as a faith-based system of government, setting precise theological parameters for acceptable policy, is over. But that means a new era of Brexit as a different cluster of economic and diplomatic headaches is just beginning.

For years, Britain’s European policy has been governed by a simple exercise in Eurosceptic geometry. Each degree of separation was a step towards freedom and prosperity. That made it easy to make terrible decisions.

Only once the ideological blinkers are removed and a pragmatic lens is applied can the full magnitude of harm done to Britain’s strategic, economic and political relations with its neighbours come into view. Every subsequent step is now harder. Success is far from guaranteed. But there is at least a chance, with a prime minister facing the right direction, using reality as the starting point.

• Rafael Behr is a Guardian columnist