My father worked as a fire warden during the Blitz, trying to contain the damage done by the Luftwaffe, and he witnessed more death and devastation than most soldiers saw on the frontline. Over a million houses in London were destroyed and nearly 20,000 civilians killed. But the horrors of the night were made more endurable by the atmosphere in the capital as day broke. All the petty distinctions that normally characterise life in a large city had fallen away. Strangers would stop and talk to each other. If anyone looked lost or confused, people would offer to help. Most adults had been up all night in makeshift air-raid shelters, often having to cope with restless children, but instead of being tetchy and short-tempered they were full of jokes and good cheer. The sense of community was so palpable, he said, it was as if you could reach out and touch it. One people united in adversity.

The resilience of Londoners during this time has been well-documented, but it’s worth repeating a few of the remarkable statistics. The psychiatric clinics opened to help people cope with the stress were closed due to lack of use. Suicides fell to below the rate they were at during peacetime. The number of work days lost to strikes in 1940 was the lowest in history. If the point of targeting civilians was to destroy morale, the Nazi bombing campaign was a failure.

I was reminded of my father’s account of this period in his life when reading about the local reaction to Monday night’s bomb in the Manchester Arena. Off-duty NHS employees volunteering to help. Taxi drivers refusing to take money from the people they drove home. Office workers interrupting their daily commute to give blood. We flatter ourselves that there’s something uniquely British about this behaviour — even something peculiarly Mancunian. But the truth is, this is how most cities react when they’re under attack. The worst of humanity brings out the best in humanity.

So what impact will this have on the election? Will it help Theresa May or Jeremy Corbyn?

My father thought that the Blitz, along with all the other atrocities inflicted on the British people by the Axis powers, helped propel Clement Attlee into Downing Street. It’s a historical commonplace that the sacrifices made by ordinary people during the second world war led to Labour’s landslide victory; having helped to save the country, they now felt entitled to a bigger share of its wealth. And my father was certainly aware of that feeling. Indeed, as the director of Labour’s research department at the time, as well as the author of the 1945 manifesto, he did his best to exploit it. But he meant something slightly different.

What he had in mind was the sense of togetherness, of unity and strength, that characterised the nation during the war. Like many idealistic Young Fabians, he wanted to build a New Jerusalem in England’s green and pleasant land, and it was in London during the Blitz that he glimpsed that Shining City Upon a Hill. How people were when dawn broke over the smoking ruins — that is how they would be in the glorious socialist republic of the future. He believed it was that Dunkirk spirit, seared into the nation’s memory, that prompted people to vote for the party that promised them a better tomorrow. The title of the manifesto was ‘Let Us Face the Future’.

Does that mean that Jeremy Corbyn will be the beneficiary of the suicide bombing on Monday? It wasn’t just an attack on a group of innocent young people enjoying a pop concert, but an attack on us all. The same collectivist ethic unleashed by the second world war has been summoned momentarily by Salman Abedi. Once again, we have seen what a utopian future might look like. Fraternity, solidarity, the spirit of 1945.

And yet I suspect it is Theresa May who will benefit. Not just because people yearn for a strong leader at times like this, but because she has the gift of being able to bring people together. To use David Goodhart’s now famous distinction, she appeals to anywheres and somewheres. Her politics — slightly to the left of centre on economic policy, slightly to the right on everything else — reflect the views of the nation in a way that Corbyn’s don’t. She is our Clement Attlee, and the British people would prefer to face the future with her.