IF ever there was a phoney war, it’s the one over a second referendum. Not phoney in the sham sense. There most definitely is a battle. Nicola Sturgeon and Theresa May are both hard as nails, utterly determined, and playing for keeps. If there is a referendum, the outcome will finish one of them. And if there isn’t, then the First Minister’s fate might be slow decline, the SNP leader who never quite got there.

What’s phoney is the tone. The protagonists are painfully polite. ‘See how reasonable I am,’ they say. ‘I only want what’s fair.’ Yet each would gladly knife the other in a flash. It’s a strange minuet, both parties dipping and curtsying, all the while fingering a dagger at their backs.

It’s because, despite constitutional jargon about Section 30 orders and LCMs, the battle is ultimately for public opinion. Hearts and minds will determine the outcome, not legal arcana. Hence each side trying to appeal to voters by being more reasonable than the other.

Be warned. Most of it is nonsense. Take Ms Sturgeon’s casus belli, her snubbed proposal for keeping Scotland in the EU single market after Brexit. It was detailed, it was thorough, and it was basically impossible. Or as it said itself: “We recognise that the options we propose will be technically and politically challenging.” Some understatement.

To pull it off would have meant the Tories, who won a majority in 2015 running as the antidote to the SNP (remember Ed Miliband in Alex Salmond’s pocket?) sacrificing slabs of their Brexit plan to strike a side-deal for Scotland and the EU 27 rewriting their rules on our behalf. And even if it was done, Ms Sturgeon reserved the right to toss it aside and call an independence referendum anyway. It was the political equivalent of saying, “I need everyone to build me a flying car - and then I want to crash it.” Funnily enough, there were no takers.

What is wasn’t, despite repeated assertions, was a "compromise" or meeting the UK half-way. It was an outlier, an off-the-chart longshot. But it helped Ms Sturgeon look reasonable and lay the ground for a referendum that had been in the post since June 23. The UK’s off-hand attitude undoubtedly helped her case on Westminster “intransigence” too.

Then, in a backhanded compliment to the FM, it was Mrs May’s turn to come over all reasonable. She didn’t say No to a referendum full stop, merely “now is not the time” because of Brexit. Again, complete cobblers. The Tory thinking is ‘You can’t lose if you don’t play’. Rather than allow a referendum that might sink the Union, Mrs May is running down the clock, trying to get past the 2021 Holyrood election in the hope a pro-Union majority is returned.

With polls showing voters against a referendum soon, the “now is not the time” mantra is a pretty decent reply in the reasonableness wars. There’s also a companion line that it wouldn’t be “fair” to make Scots choose between Brexit and independence before all the facts are in, a formula so elastic it could mean decades. One SNP strategist I spoke to gave the Tories grudging credit for the approach. The question for Ms Sturgeon is how to overcome such slipperiness.

She’s talked of further “steps” to secure a referendum after Easter. Gumming up the Holyrood side of the Great Repeal Bill is an option. But don’t expect fireworks right away. In the first instance, listen out for a new refrain on “the right to choose” and Scotland’s view on a referendum. After all, what could be more reasonable than rights and choice?

So hunker down for a waiting game. The battle for public opinion will be long and stealthy rather than short and noisy. Both players are smiling sweetly, but itching to attack. This being politics, the winner is likely to be whoever can maintain the phoney pretence the longest.