OF all the broadcast interview tropes that must be learned by politicians, perhaps the most tricky - and revealing - remains the leadership question. It usually goes a little something like this: journalist asks said politician whether they would be interested in leading their party, and said politician (usually a member of the cabinet) instantly becomes overly demure, seeming to scoff at the very idea, says their boss is doing an excellent job, and everyone should get behind her/him, adding that they already have an “important job” to do.

All three of the parties involved in such interviews – journalist, politician and audience – know that this kind of talk is actually shorthand for: “I’d do anything to get my hands on the leadership/Number 10 and am already sharpening the knives for when I can plausibly get away with plunging them into the back of my boss”. Let’s be honest, it’s all part of the fun.

There are always exceptions, however. And despite increasingly feverish speculation, when Ruth Davidson told Andrew Marr and Robert Peston yesterday that she had no intention of challenging Theresa May for the UK party leadership, for once it rang absolutely true.

Mrs May isn’t Ms Davidson’s boss as such, of course, and this just makes the dynamic all the more intriguing. But I don’t believe for a minute that the Scottish Tory leader is seriously thinking of making a play for the top job, even though the voices urging her to do so are getting louder by the week.

And it’s not just the Tory constitution, that doesn’t allow someone without a Westminster seat to be party leader, that’s in the way. Constitutions can always be changed, situations can be devised that would allow things to happen. It’s not just that an openly gay young Scottish woman with a penchant for kickboxing might be a step too far for the party grassroots down south. No, I reckon it’s more that Ms Davidson knows fine well she’d be off her rocker to take on the job, at least for now.

Following Mrs May’s disastrous speech at the party conference last week, I wouldn’t be surprised if the MSP for Edinburgh Central, whose own speech wowed many in the Tory ranks, was bombarded with texts from party colleagues in England encouraging her to make a move now or in the near future that would save the party from Boris or Jacob Rees-Mogg.

Ms Davidson, of course, is an increasingly attractive proposition for many Tories in the south, particularly those who voted remain and seek a leader who can bring Britain back from the edge of the No-deal Brexit cliff Mrs May and her colleagues have insisted on walking us all towards. Those towards the centre of the Tory spectrum look north and see election success, administrative competence, a narrative about creating a more modern brand of British rather than English Conservatism and, crucially, an ability to come across as a human being, and are hooked. It must be hard for Ms Davidson, meanwhile, not to get too carried away by the flattery; surely every non-SNP politician harbours a desire to get their hands on the keys to Number 10?

The reality, however, is that Ms Davidson, or indeed anyone else who might be tempted to make a leadership challenge, would be choosing to pick up a poisoned chalice in the full knowledge that it has just been newly topped up with toxins. This is a party, after all, that is not only divided, but ripping itself to shreds on every possible front. It has no vision for either itself or the country, despite selfishly taking us to the aforementioned cliff-edge, and talks hollowly of duty and responsibility while playing cruel ideological games with the lives of not only the have-nots, but increasingly those in the majority who have a bit but can’t afford to lose any of it.

Last week’s chaotic Tory conference let not one, but a whole troupe of cats out of the bag. And, as competent an administrator as she may be, not even Ms Davidson could – or would surely want to - herd them. There aren’t so much two factions battling for control of the Conservatives, but multiple groups with radically different agendas. To add to the pressures, weary voters in England are increasingly turning to Labour.

Compare all this to Ms Davidson’s position in Scotland: stable, unified party, star still rising. You wouldn’t touch the English Tories with a bargepole.

More likely you would watch with interest from the sidelines and see if you could get some concessions during the Brexit negotiations that may help shore-up your position at home. Let some other lamb to the slaughter take over from Mrs May in the short term and try to get a some sort of deal out of the increasingly hostile EU, while the party unfaithful keeps twisting the knife.

Further down the line, Ms Davidson may take a different view; in these craziest of times, anything can and apparently does happen.

The Westminster Tories certainly need something or somebody to save them (and indeed the rest of us) from themselves. But for now, Ruth Davidson is savvy enough to stay out of the quagmire.