Labour is a pro-EU party.  It is also the Opposition, with an appetite for Government, at least in some quarters.  It follows that it is in its interests to stop Brexit, thereby weakening if not destroying Theresa May, even if Jeremy Corbyn has a soft spot for leaving the Union.  (“We all knew Jeremy was against [the EU],” Alan Johnson has said. “He’s not changed his mind on anything since he was 15, why would he change his mind on that?”)

None the less, Labour cannot be seen to block Brexit.  The electoral perils are too great.  Too much of the party’s white working-class base voted Leave for it to risk openly defying the referendum result.  This is a point that Labour MPs in the Midlands and North are particularly conscious of, and Donald Trump’s victory from the outside in America’s presidential election has left them very nervous.

All of this explains why the party both folded and split when the Government put Article 50 to the vote yesterday evening.  It folded, because Keir Starmer and its front bench did not dare oppose the move.  And it split, because Labour’s most committed pro-EU members could not bring themselves to support it, especially if their constituencies are in the Remain-trending parts of London and the South.

Rushanara Ali from Bethnal Green and Bow, Helen Hayes from Dulwich and West Norwood, Meg Hillier from Hackney South and Shoreditch, Peter Kyle from Hove and Portslade, David Lammy from Tottenham, Tulip  Sadiq from Hampstead and Kilburn, Daniel Zeicher from Cambridge: all these went through the No lobby, together with a handful of Blairites, Remain partisans, MPs with non-English seats and prospective retirees.

There were 23 of them altogether, and a further 56 abstentions, according to the Conservative Whips.  That’s a bad result for Keir Starmer: it looks today as though the Government has out-manoeuvered Labour front bench, dividing it in yesterday evening’s vote, but conceding little of import in relation to the publication of its negotiation aims.  But we will see.

So what could bring the whole party, the SNP, the Liberal Democrats and Conservative pro-EU MPs together against Theresa May?  (Only one of the latter voted against the Government yesterday: Ken Clarke.)  Amendments to the Great Repeal Bill could do so (as could a full Brexit bill, if the Supreme Court insists on one).  During the 1990s, John Smith opposed parts of the Maastricht Bill, which he supported, in order to do down John Major.

Its modern equivalent would thus be a kind of Smith-in-reverse.  Any Bill which proposes to freeze current EU regulation in aspic looks especially vulnerable to amendment.  So don’t presume that last night’s sweeping victory for Brexit is anywhere near the end of its Parliamentary story.  Before the division took place, the Commons had a pro-EU majority, and so it does afterwards.  It dare not kill Brexit, but it will not strive officiously to keep it alive.