John McDonnell, the softly spoken “street orator” and avowed Marxist intent on colonising the centre ground, is running late. Stephen Kinnock, a persistent Corbyn critic working with the Tories for a softer Brexit, emerges first from his office. A few minutes later comes Ivan Lewis, who resigned from the party the next day in protest at the Labour leader’s failure to address antisemitism.
Mr McDonnell, 67, was once seen as the menace behind Jeremy Corbyn’s grandfatherly charm. In recent months, however, he has emerged as the figure to whom Labour moderates turn for reason. The shadow chancellor is doing his damndest to hold Labour’s dysfunctional family together.
How much did his long spell running a small children’s home with his first wife prepare him for what he does today
“The one thing you try and have when you’re looking after children is empathy,” he says.
“I think that’s the most valuable lesson, empathy as much as possible. But, at the same time, with children you have to set parameters as well. What I try and do is empathise as much as possible but also set a few parameters.”
He says that he has been talking to all sides of his party, which represents some of the most pro-Leave and pro-Remain seats in the country. Some Labour MPs believe the leadership is dragging its feet over a no confidence vote in the government because it is committed to considering another Brexit referendum if it fails to trigger a general election.
Mr McDonnell denies that. He has “always urged people to be savvy” about a no confidence vote, he says.
Will Labour table one in January if, as expected, MPs vote down Theresa May’s Brexit proposals? He cautions against making predictions, saying: “It depends on those unique circumstances and, of course, it depends on the Democratic Unionist Party (DUP).”
If the party does move on to examine other options, including another referendum, he suggests that Labour members hoping for a say will be disappointed. Asked if the rank and file would decide the party’s stance on another Brexit vote, he replies: “I can’t see it, but anything can happen. At the moment, it’ll be the usual consultations that will decide it.”
These discussions will take place within the shadow cabinet and among Labour MPs, he says.
He smiles at the mention of the DUP, the kingmakers in a hung parliament because of their confidence and supply agreement with the Conservatives. As a supporter of a united Ireland Mr McDonnell is far from a natural bedfellow for the staunch Unionists.
However, he says that the two of them could have a fruitful relationship if Labour were in government. “This is a funny thing, I know — despite our differences around the issue around united Ireland and matters related to that, I’ve always had a good relationship with them,” he says.
He has always been able to talk to DUP MPs, he says, because “it’s always been on the basis of this is where we stand on a number of issues. Remember, they have a very large working-class community that they represent.”
“I can see a joint working programme,” he adds. “I can see them voting for policies that we’d advocate when we get into government.”
These would include “social investment, tackling the social security crisis that they’ve got in Northern Ireland, building the homes that they need, making sure their schools are properly funded and the NHS properly funded”.
Before any of this, Labour first has to win a general election and the next one is not due until 2022. Lord Kerslake, the former head of the civil service, is working with the party on its preparations for government.
Also involved, perhaps more surprisingly, are figures from the New Labour era. Mr Corbyn, 69, was famously a thorn in the side of Tony Blair and Gordon Brown’s governments, voting against them 500 times.
Nevertheless, those prepared to help the party include Labour’s last prime minister, says Mr McDonnell. Eleven years ago, Mr McDonnell was the only Labour MP to try to halt Mr Brown’s coronation as party leader and prime minister, although he couldn’t muster enough support from colleagues to make it into a contest.
“Gordon Brown and others have always said that whatever assistance we need is open to us.” He even says he wants to build on Mr Brown’s legacy.
One of the issues the shadow chancellor says that the party is keen to address is “how can we make sure that we’re tackling the problems of child poverty, which Gordon Brown went so far on, but we think we’ve got to set a target of eliminating it”.
A Treasury under Mr McDonnell would be given a mandate to look at inequality and climate change. And, despite the criticism the party would face, he is unafraid to talk of Soviet-style five-year plans.
His Treasury would begin a spending review in the first year, he says. “The spending reviews at the moment are three-year programmes. We’re looking for a five-year programme. The idea behind that is to start setting targets around each element of expenditure as well,” he says.
He is also preparing for an emergency budget within two months of getting into power. Labour has told the Office for Budget Responsibility to cut the time it takes to prepare for a budget from ten to eight weeks to “have the budget as soon as we possibly can”.
With Labour setting out its stall, Mr McDonnell is asking for input into the appointment of the next Bank of England governor, even though he is still shadow chancellor. Although Mark Carney is not due to leave until January 2020, replacing him will be a long process.
An independent report for Labour on financial services includes “a significantly new role for the Bank of England for a strategic investment board, so the idea is to make sure whoever goes into that role recognises the key role that they’ll play in direct investment”, he says.
Labour accused the government of stealing a number of its policies in October’s budget. Mr McDonnell says that the party should be flattered and denies that it is a sign that he and Mr Corbyn are not radical enough.
“Yes, they steal [policies] but they’re really so useless they can’t implement them effectively,” he says. “They do it in a half-hearted way. They’re not really committed, so it’s just seen as tokenism, really.”
He adds: “It means we’re winning the arguments. It commonsense socialism. We’re all socialists now.”
Perhaps with one notable exception, he concedes, although he then claims: “Theresa May wants to be a socialist.”
He adds that he had recently handed some Tory MPs in the Commons chamber “an application to join the Labour Party. I suggested that some of them might want to look at it.”
It is the Corbyn-led Labour party that occupies the centre ground, he says. “I think we’re identifying the issues that need to be addressed. We’re identifying the solutions that people generally accept are the right solutions and we’re dominating in terms of the intellectual debate.
“However you judge it, if you’ve got a majority of opinion, obviously you are demonstrating you’re right the way across to be the centre. Of course you have to. You have to capitalise the centre if you’re going to get into government. That’s what we’ve done, we’ve expanded our base.”
That leaves an obvious question. How do you translate that into votes? The answer, he says, is in “more effective communication of those ideas using whatever mechanisms we possibly can, using whatever media we can”.
One of the fears of many centrist Labour MPs is that they will be deselected by their local parties and replaced by Corbynites. Mr McDonnell says he thinks that deselections will continue to be very rare. However, he appears to suggest that it is up to MPs to make sure it does not happen to them.
“It’s not difficult to maintain a good relationship with your constituency party,” he says.
“It really isn’t, because even where there’s difficult differences, there’s an understanding that there will be difficult differences. As long as you represent the party effectively and as long as you do the work on the ground, it’s very rare to deselect someone.”
He does believe that the party needs to do more to improve its relationship with the Jewish community after months of accusations of antisemitism.
Mr Lewis, who is Jewish, accused the Labour leadership of delaying an investigation into sexual harassment claims against him for political reasons but also told Mr Corbyn: “All too often you have been unwilling to condemn those whose hatred of Israel becomes Jew hatred.”
Mr McDonnell says that the party’s relationship with the Jewish community is one “we work at all the time”.
He says that Labour is also working hard to “make sure this society isn’t divided because of the Brexit issue. I’m really worried about that.”
Some have accused Mr Corbyn and Mr McDonnell of being dangerous radicals. Instead, he insists, they are boring. He reveals that the last Christmas present he received from his party leader was the tie of his beloved Liverpool Football Club.
The last gift he gave Mr Corbyn, who makes jam from his own fruit, was a book on the history of allotments.
“I think it was either for his birthday or Christmas,” he laughs. “Are we stereotypical or what? We’re boring, aren’t we? Well, he loved it.”
He adds: “Then I got him another book, it was the history of the railway system, because they’re his two loves.”
When he is not preparing for a socialist government, Mr McDonnell is learning to play the trombone and in particular When the Saints go Marching In, with its references to the Book of Revelation.
He admits that, as tunes go, “it’s the simplest and easiest one. I haven’t had much time to practise.”
He hopes that soon all the hard work will pay off, and instead of Labour backbenchers filing out of his office, it will be some of the most important players in world finance.