'Now is not the time' is not an answer to anything, not least since no one has actually suggested a second referendum on Scottish independence take place 'now'. In that respect, the Prime Minister's line today answers precisely nothing and cannot be sustained inevitably. I should have thought this sufficiently obvious enough that even people in Downing Street could have discerned this. But evidently not.

The SNP are past-masters when it comes to mining grievance. That being so, however, you wonder at a strategy that hands them a gold-plated grievance and does not even seek to charge them a fair price for it. Theresa May might as well have said: 'Here, have this one for free'.

So of course Nicola Sturgeon considers the Prime Minister's reluctance to allow a second referendum some fresh 'democratic outrage'. That's what the first minister is there to do. And it is true that if it weren't this, it would simply be something else.

Nevertheless, since a Section 30 order allowing a legal referendum would take at least a year to organise, it was already vanishingly unlikely that there could be any referendum by the end of next year, the notional timeframe Sturgeon suggested on Monday. That was never an entirely realistic prospect, of course, and the first minister knows it. This, it should be obvious by now, is a question of positioning.

Which – again! – makes one wonder why Downing Street can't appreciate that kindness kills more effectively than a blunt dismissal. There is as yet little enthusiasm in Scotland for a second referendum but, if there must be a fresh plebiscite, the notion it should not be held until after a Brexit deal with the EU has been accomplished is one that is intuitively reasonable. The sort of thing that, in the end and when you boil everything down to their essentials, satisfies most people's sense of fair play. It would, I think, be an easy thing to sell.

But then Downing Street has form when it comes to missing obvious opportunities. There was, for instance, no need for it to reject the Scottish government's proposals for a differentiated Brexit deal in which, in some mysterious way, Scotland would remain a member of the single market while the rest of the UK left it. No need, that is, for Downing Street to abruptly, even rudely, reject it when that work could have been left to the European Commission. Let them play the villain, just for once.

In truth, this latest outbreak of nationalist whining has a saccharine quality to it. The SNP are not likely to be terribly disappointed by the Prime Minister's remarks today. Those remarks feed into and nourish their longstanding story of a Scotland let down by an arrogant, out of touch, and careless Westminster government. So, again, one wonders why the UK government is so happy to give the SNP what they want?

The further problem is that once the Scottish parliament has voted for a fresh referendum it is difficult to maintain the fiction that there is no demand for a second plebiscite. Unless, that is, parliaments are now to be thought utterly unrepresentative of the peoples they serve. And, whatever my friends in the Scottish Conservative and Unionist party may say, the SNP at least have a clear and plausible mandate for a second referendum. If that upsets Tories they might remember that it wouldn't be happening at all if it weren't for Brexit (which, of course, is part of the reason why Ruth Davidson campaigned so ardently against Brexit. She could see what was coming). You broke it; you own it.

Reasonableness matters and has an effect. At the very least, being seen to be reasonable matters and has an effect. There are ample grounds for thinking the SNP's professed position modestly unreasonable, not least since it's not easy to see how you can demand a referendum in response to Brexit before the precise detail of what Brexit looks like is established.

Instead, however, the UK government decides to offer a non-answer to a question that wasn't even being asked. The actual question that matters is 'if not now, then when?' and as best I can tell the Prime Minister hasn't a clue how best to answer that.

In any case, the SNP won't be particularly worried by the thought of the can being kicked down the road to 2019 or even, perhaps, the autumn of 2020. As Ruth Davidson has suggested often enough, the UK government cannot rule out a second referendum 'forever' and nothing that happened today changes that. Indeed, implicitly 'now is not the time' concedes that there must be a time at some point. That being so, it would be sensible to say so.