Yesterday morning, we described the strategic choice facing Boris Johnson.  Should he seek an election now, and risk having it before Brexit?  Or should he complete Brexit now – by driving his Withdrawal Agreement Bill through Parliament – and risk missing out on election victory this autumn?

The Prime Minister’s response is ingenious.  It is to challenge Labour to pass the Bill and then contest an election on December 12.  This way, he would get Brexit done and have his snap election – “just like that”, as Tommy Cooper used to say.  And if Labour refuses him, he and the Government will simply down tools.

Team Johnson knows perfectly well that Labour is unlikely to agree to not just one but two things it opposes: the Bill (because the party tends to object to anything the Government proposes) and an election (because the polls suggest that it would lose).

No, the offer isn’t really designed to do what it says on the tin.  Rather, it has been crafted, first, to obscure the fact that the Prime Minister will not now meet his October 31 Brexit deadline; and, second, to put a tiger among Labour’s pigeons.

Jeremy Corbyn himself seems keen on an election.  Momentum certainly is.  But lots of Labour MPs certainly aren’t.  Some represent Leave constituencies, and think they might lose.  Others want a second referendum rather than an election.  Others still have no confidence in Corbyn himself.

Johnson’s offer seeks to widen these divisions.  The Labour leader’s leitmotif is that he opposes No Deal and wants a general election.  But if he’s really against No Deal, why not agree to consider the Bill – thus taking No Deal “off the table”, at least until the end of transition?  And if he really wants an election, why keep voting against one?

Yesterday, Corbyn was reduced to saying that he’d respond to the Prime Minister’s challenge once the EU makes up its mind about an extension.  This takes us to that decision itself – because Johnson’s gambit is aimed at the EU as well as Labour (and the voters).  This is its third purpose.

If you offer the long extension that most expect, he is saying, it will avail you nothing.  For when Corbyn rejects our offer – as he is likely to do – we will sit on our hands.  No return for the Bill.  Little Parliamentary activity.  Instead, my Government will simply keep calling for an election day after day after day after day.

So at the end of any long extension, he is suggesting, the Commons will still be where it is now: with the Bill having achieved Second Reading, but not moved on to its further stages.  In which case, the extension will have failed to force the issue.

We therefore can’t help reading the Prime Minister’s ploy as a double-forked manoeuvre.  Prong one is putting Corbyn on the spot.  Prong two is suggesting to the EU that a long extension won’t achieve anything – so it should offer a short one of a few weeks at most, and thus confront MPs with that choice: Johnson’s deal or No Deal.

The manoeuvre could blow up in the Prime Minister’s face.  Voters could decide that missing the October 31 deadline is unacceptable (since Johnson will neither have done nor died).  They could blame him for playing Parliamentary games amidst a serious crisis.

Or Labour could pick up the gauntlet, accept the Prime Minister’s challenge, seek to amend his Bill out of all recognition, and out-campaign the Conservatives in the election – as they did in 2017.  It is extremely unlikely that the turkeys will vote for such a Christmas poll, but one never knows.

For all that potential downside, everything that doesn’t kill Johnson seems to make him stronger.  His Government has been routinely defeated in the Commons.  His majority has plunged to minus 43.  His prorogation was quashed by the Supreme Court.  He was forced by the Benn Act to apply for an extension,

Yet his poll ratings are remarkably buoyant.  It is no mean achievement to have won a Commons majority in principle for a Brexit policy at last.  And yesterday, his Queen’s Speech sailed through.  For all that lack of a majority, he is on the front foot – throwing down challenges, taking the initiative.

The Prime Minister grinds on like some giant armadillo, inching his way across hazardous terrain.  If, as expected, the EU offers a longish extension and then – as also expected – Labour refuse his offer, that ground could become a Parliamentary wasteland: no Bills; no votes of any significance; Commons stasis.

The mills of Johnson grind slowly, but they grind exceeding small.  The most likely course of events will see him challenging Corbyn to an election again and again and again until the latter’s nerve cracks – or Labour’s refusal to contest a poll makes it an object of ridicule even among those who don’t follow politics.