ANALYSIS: The Tories, not Ukip, are benefiting from Labour's northern nightmare
The morning after the EU referendum, I took a call from a rather perplexed Labour MP.
Jeremy Corbyn had to go, he said. With him in charge, Labour would be slaughtered in the north.
But he said the beneficiaries would not be Ukip, as many were predicting, but the Conservatives.
"Some of our people will switch to Ukip, and the Tories will come through the middle," he said. "Voters will also look at Jeremy and decide they don't want him to be Prime Minister, even if they're Labour supporters. We will get annihilated right across the north."
His solution was for the Shadow Cabinet to rise up and demand that Corbyn quit. Well, we all know how that turned out.
Exactly eight months later, however, and the MP's prediction is starting to come true.
Labour did manage to hold on last night in Stoke-on-Trent Central, although their vote share went down while both the Tories' and Ukip's increased.
But in Copeland, an area Labour has held since the 1930s, the Tories won the seat on a swing which would deliver a three-figure majority for Theresa May if repeated at the next election.
For Theresa May, the by-elections could not have gone better. Humiliation for Ukip leader Paul Nuttall in Stoke, plus an extra Tory MP to help bolster her less-than-chunky Commons majority. And Jeremy Corbyn clings on.
As ever, it was left to John McDonnell to spin the Labour line on the TV and radio this morning. By far the best media performer in the Corbyn camp, he played a dreadful hand as best he could, but there were a few Comical Ali moments.
When asked whether Corbyn's position is under threat, he said "it's not about individuals". That argument was undermined somewhat when he then went on to blame Tony Blair and Peter Mandelson for their recent criticisms of the party. Nuclear power, Brexit and rebellious MPs were also blamed, as the Shadow Chancellor insisted the party leader's position is secure.
He's right, for now. No moderates are willing to put their heads above the parapet following last year's failed coup, and those on the left are still standing by their man.
Paul Nuttall is probably under more pressure, not least because Nigel Farage – who has never really gone away since stepping down as leader – warned last week that victory in Stoke was a must.
Meanwhile, despite a tricky few days in which the Government has been left looking foolish over business rates, Theresa May ends the week in a stronger position than she began it.
She must scarcely believe her luck.