The meaning for Theresa May of the vote on the 'meaningful vote'

After her disastrous general election in 2017, May is being judged on the Brexit she delivers Credit: PA

This afternoon’s vote in the Commons on whether MPs should have a more meaningful “meaningful vote” on the terms of Brexit has become a test of the prime minister’s authority and ability to govern.

But I am not sure it had to be. Because the clause demanded by the rebel Remainers, led by Dominic Grieve, does not seem to constrain Theresa May in the way she alleges and fears. Or to put it another way, May could have swallowed the substance of the amendment and emerged unscathed.

Now of course if she loses - and that is a very real risk for her - she would be crocked worse than Alli at the World Cup.

Grieve’s amendment - rebadged in the Lords on Monday as Hailsham’s - would force the government to put an “amendable” motion to Parliament after 21 January 2019 in the event that no Brexit deal has been agreed with the EU - or no deal had yet been voted on by MPs.

Since opinion in Parliament is definitively against a no-deal Brexit, this clause is seen by May as removing her ability to threaten the EU with a no-deal Brexit.

But it is very difficult for anyone - the EU or bystanders - to see no-deal as a genuine bargaining chip in any case.

EU governments could hold the threat of a "no deal" Brexit over the UK in negotiations Credit: PA

Apart from anything else, other EU governments are crystal clear that no deal is worse for the UK than for them - especially in its impact on living standards.

They showed this yesterday with a leak of the forthcoming EU summit’s draft conclusions, which effectively threatens us with no deal, rather than vice versa.

Also, and as the Tory leader of the Lords Baroness Evans conceded on Monday, any motion in January 2019 directing the government on Brexit next steps would only have symbolic value - it would not be “justiciable”, it would not have the force of law, it would guide the PM rather than bind her.

Finally, all this fuss about what status such a vote would and should have is the precise equivalent of an argument about where the reclining chairs should be placed on the Titanic.

Anti-Brexit campaigners outside the Houses of Parliament this month Credit: PA

The big political fact, which the PM surely knows, is that were there no deal with the EU so soon before the day of Brexit on 29 March, May would have catastrophically failed in more-or-less her only task of importance.

After her disastrous general election of 2017, she is being judged on one thing and one thing only: whether she can negotiate an adequate exit from the EU.

No deal would for her be the mother of all failures (and let’s not get into what it would mean for the rest of us). So if that was what she brought back from Brussels to London, she would be toast, history, caput.

The idea therefore that Grieve and co are trying to put her in a straitjacket is a joke - because she has already been fitted for it, and she’s wearing it for all to see.