But Tories finished him off

voters backed staying in. True, there was one part of Labour Britain where Remain did well – London, gaining no less than 60 per cent. But it is a very different kind of Labour Britain.

The capital is far more ethnically diverse and Leave’s anti-immigrant message had not gone down too well amongst those from a Black or Asian background. At the same time, London has many more younger people and graduates than anywhere else in Britain. It was always going to be fertile territory for Remain.

The North and the Midlands have the supposedly more traditional Labour voter – white, working-class and proud of it. Their disaffection, it was argued, was the source of Remain’s problems.

There is no doubt that swinging this section of Labour support behind Remain was always going to be difficult.

One of the key social divides in this referendum was between middle-class graduates, relatively comfortable about immigration, and working-class folk with few, if any, qualifications for whom immigration can look like a threat to their jobs and their culture. Indeed, on average Leave won no less than 64 per cent of the vote in those council areas in England and Wales with relatively few graduates, compared with 42 per cent where graduates predominate.

It explains why Remain did so badly in much of the North and the Midlands. There are simply fewer graduates there.

Meanwhile, a strong Labour presence locally was a help rather than a hindrance. For example, in council areas in England with relatively few graduates Leave did a little less well in places where Labour is relatively strong locally (62 per cent) than where the party is weak (67). Where graduates are more plentiful, the Leave vote was a full 13 points lower where Labour was strong.

By contrast, the opposite is true of the Conservatives.

In those parts of England and Wales with lots of graduates, Remain support was much lower where the Tories are strong locally (55 per cent), than where they are weak (70). A strong Conservative presence locally made ‘What we need now is Scotland’s governments working together for stability. Agitating for a referendum rerun will do precisely the opposite’ life more difficult for Remain. We should not be surprised.

For all the difficulties Labour may have had with persuading its voters to back Remain, according to an on the day poll conducted by Lord Ashcroft 63 per cent of those who voted Labour last year backed Remain; YouGov reckon it could be as high as 69.

Yet only a minority of those who voted for Mr Cameron 12 months ago supported him in the referendum – Lord Ashcroft put it at 42 per cent and YouGov’s estimate of 43 was much the same.

Ultimately, the real source of Mr Cameron’s difficulties lies not in the handsome wins that Leave enjoyed in such Labour heartlands as Bolsover and Blackburn but rather in his inability to carry the day in many a Tory heartland, such as South Buckinghamshire, Chichester and the New Forest.

Blaming Labour for Remain’s defeat may look like the obvious explanation but the makings of Mr Cameron’s downfall lie much closer to home.

He failed to carry his party with him and is now paying the price.