Andrew Harrop (pictured) says Labour must adapt if it is to grain groundWellcome Collection

Where is the Labour party going after Brexit? For those on the left, this is the question du jour and one which elicits a wide variety of responses – most of them either doom-laden or vaguely utopian.

And it is also one which Andrew Harrop, General Secretary of socialist organisation the Fabian Society and a leading voice within the Labour movement, is faced with regularly. So it was perhaps to be expected that he is able to explain the party’s predicament with remarkable clarity.

Labour, he tells me, is a broad coalition which encompasses both traditional white working class and more liberal, cosmopolitan voters. Its electoral success is dependent on appealing to both groups: unless the party brings together a wide range of voters, it will fail.

Brexit has brought to the fore of British politics a number of social and cultural issues, especially surrounding migration, which divide Labour voters. The result, Harrop tells me, is a “very difficult situation: although a sufficient number of people would support a left-wing economic agenda, it’s very hard to find consensus on culture, migration and membership of the EU.”

While this is an analysis that Harrop has clearly delivered before, it does not feel rehearsed. It begs an obvious question, though: can Jeremy Corbyn achieve such a broad coalition? Or will he necessarily alienate some elements of it?

Here Harrop pauses: the issue of the Labour leadership is a perennially delicate one. In 2016, the Fabians were accused of facilitating a centrist coup against Corbyn and recent speculation about Labour evaluating potential successors is likely at the forefront of his mind. Despite that, he does not pull his punches.

“It can’t go on like this for another four years until another election, or else Labour will be defeated very heavily”

“The paradox of Jeremy Corbyn is that he’s been very successful in mobilising around half a million people, whose political commitment has been massively intensified,” Harrop explains. “But he has not reached out beyond that. He is a paradox – a sort of unpopular populist. He is able to sweep the board in Labour Party internal elections but the evidence so far is that he is not reaching former Labour voters and people who are undecided. You can see that in the Labour Party’s overall polling, which is not… you know…” Harrop pauses to grimace before continuing: “It’s not absolutely desperate but similar to 2010. However, Labour’s midterm polling tends to play better than the eventual election result. It could even be worse.”

As I nod, slightly surprised by his answer, Harrop goes on: “Jeremy’s personal polling ratings, in terms of people’s confidence in him as a person, aren’t good enough. But everybody in the party wants Labour to do better and that includes people’s perceptions of Jeremy as a leader. We need to see some improvement, though. It can’t go on like this for another four years until another election, or else Labour will be defeated very heavily.”

Aware that I’m blundering through potentially dangerous territory, I shift the focus to Labour’s potential rivals. If the party does continue down the Jeremy Corbyn track for the next four years, then it will vacate the political centre. I ask him whether a Liberal Democrat resurgence is possible in the middle ground and what impact that might have on Labour.

Harrop is largely unconcerned: a Liberal resurgence is a possibility but, “at a national level, it’s not going to be a threat to Labour”. He points to the example of the 1990s, when Labour and the Lib Dems moved forward together against the Conservatives. “There will be a handful of seats where Labour and the Liberals compete against each other but, for most of the country, it’s clear which of the two are the viable centre-left party – and they’re facing the Conservatives. Remember: the reason the Conservatives have a majority is because the Liberal Democrats melted down in the last election; Labour actually gained a few seats in England and Wales. The problem was Scotland, not what was going on south of the border.”

“Labour does need to be more in tune with the middle of the road of public opinion. It can’t be an ultra-liberal, university town party – it has to strike a balance”

Harrop is equally unconcerned by UKIP’s nativist appeal in the north of England. When I suggest that Labour is challenged by UKIP’s northern growth, he quickly corrects me. “The real challenge to Labour in the North, as with everywhere else, is the Conservatives. UKIP will take some votes off Labour but we have historically lost out to the Conservatives.”

He does not think that Labour’s electoral prospects are entirely rosy, however. “If things carry on going as badly as they are at the moment, then Labour could go down to 150 seats – certainly under 200. And almost all of those seats would be lost to the Tories, not to UKIP or the Lib Dems.”

The cure for this potential electoral disaster? For Harrop, the situation demands a delicate political balancing act. “Labour can’t be a fake, sub-UKIP party,” he explains. “It’s not in its values and it would look totally insincere. It can’t try to ‘out-UKIP’ UKIP or mirror the authoritarian streak of the Tories. But it does need to be more in tune with the middle of the road of public opinion. It can’t be an ultra-liberal, university town party – it has to strike a balance.”

Harrop smiles, appreciating the irony of the situation: a Cambridge graduate himself, he is about to address precisely those ultra-liberal university students who propelled Corbyn to power and will now have to compromise.

“Of course,” he says, “the ultra-liberal side of the left shouldn’t be dismissed, but that’s not where the middle ground of public opinion is. And the middle ground is not where the Labour party is at the moment,” he says, making clear that, in his view, the followers of the unpopular populist that is Jeremy Corbyn have got some thinking to do