THE resignation of Britain’s ambassador to the US Sir Kim Darroch illustrates the continuing crisis gripping the British state and the Establishment.

His departure following the favourite to be the next PM, Boris Johnson, declining to guarantee his position exposes tensions between Johnson’s right populist politics and the state machine he hopes to lead.

These tensions are familiar from across the Atlantic. Johnson’s hope is that he can emulate the Trump model: ride to power on a wave of nationalist anger at elites while actually representing the most reactionary and extreme sections of the capitalist class.

The Republican Party machine was not pro-Trump. Former leaders like George W Bush attacked his vulgarity and racism. But the party sensed that in a crisis of capitalism only a party that could appeal to public anger had a hope of winning.

In a purely party political sense, they boxed cleverer than the Democrats, who rigged their selection process to prevent the anti-Establishment candidate Bernie Sanders — who polls showed beating Trump — from leading the party, using so-called “superdelegates” to hand the crown to Washington insider Hillary Clinton.

Trump was able to inflame anti-Establishment anger against Clinton to great effect, winning him the White House.

But the Democrats’ decision was not purely party political. Their machine did not choose Clinton because it mistakenly thought she would be the strongest candidate.

It rejected Sanders because he represented a threat to the power and interests of a ruling Establishment that dominates the Republicans and Democrats alike, and to whom even a Trump presidency is preferable to the whiff of socialism.

There are serious lessons here for those in the labour movement fighting to elect a transformative Labour government.

Large sections of the elite detest Johnson and yearn for a so-called “centrist.” If only Labour could return to the “centre ground” it would surely wipe out the extremists at the helm of the Tory Party, columnists such as Matthew d’Ancona argue in the Guardian.

Veteran Establishment journalists such as former Telegraph and Evening Standard editor Max Hastings argue that Johnson wouldn’t stand a chance against a normal Labour leader, but could defeat Corbyn because he is even more unpalatably extreme.

We’ve seen this guff before — it is how the monopoly media treated Corbyn’s election as Labour leader and the reason Labour’s 2017 advances bewildered what was once known as the “polite world.”

That echo chamber of the elite was equally wrongfooted and offended by 2016’s public vote to leave the European Union.

The claim — stressed by many Labour MPs and their media cheerleaders — that the public have changed their minds is based on wishful thinking rather than evidence.

But its advocates have succeeded in forcing a retreat by Labour’s left leadership on the EU, bringing it closer to the Establishment’s preferred Remain position.

This is dangerous for Labour for the same reason that picking Clinton was dangerous for the Democrats.

Committing to support for an undemocratic pro-corporation bloc that institutionalises capitalism undermines Labour’s credibility as a radical insurgent force in British politics.

It is that radicalism that saw it leap forward in 2017 after years of falling votes under Blair, Brown and Miliband.

Like the US superdelegates, some Labour MPs don’t care that this policy makes it harder to win an election if it helps neutralise the real danger to the ruling class they serve — a socialist leader of their own party.

The labour movement has a different class to serve, one whose interests demand the radical overhaul of Britain’s economy Corbyn promises.

That overhaul requires much greater clarity throughout the organisations of our class on the nature of the EU, and a grassroots movement strong enough to help Corbyn resist pressure to reduce Labour to the dull pro-capitalist managerialism that has seen the US Democrats and most of the European social democrats routed by the right. That battle is the radical left’s responsibility. It is not yet lost.