"NO” is a powerful word. And it is, it would seem, the only word Scottish Tories want to hear.

An odium of contenders has already come forward to replace Theresa May, whose final punishment will be to greet liberty’s great addled watermelon, Donald John Trump, during his second state visit to the United Kingdom this week.

There’s the presumptive front-runners – your Gove and Johnson and Javid, the Hunt and Raab. Wee Rory Stewart is lurking somewhere in the rhododendrons, pursued by Andrea Leadsom, Nurse Ratched’s spiritual heir. And don’t forget the final three – Kit Malthouse, James Cleverly and some randomer called Mark Harper, all of whom, proverbially, aren’t household names in their own households.

The Scottish Tories are looking for the Yoon to Yoonite them all, and the prospect of a second independence referendum is giving the leading contenders an opportunity to flash their garters to Ruth Davidson’s MPs and members.

In case you were hoping for anything more subtle or constructive, “enhancing your Unionist credentials” these days mean howling “never, never, never” into a microphone. Theresa May’s nuanced line on a second referendum – “now is not the time” – has been replaced by harder responses from those hoping to replace her. Their script, essentially, is that Holyrood’s pro-independence majority should get stuffed.

It’s been Sajid Javid making the biggest headlines this week. The angry double-yolker tweeted “if I become PM, I won’t allow a second Scottish independence referendum. People stated views clearly in 2014, so there should be no second vote. Nicola Sturgeon should spend more time improving public services in Scotland, and less time grandstanding”. In his attempt to win over a tough crowd, it is difficult to imagine Boris Johnson taking a different line.

Most of the Scottish media seems content to treat these pronouncements of “no, nein, nyet” as if they’re a neutral fact of political life, quietly to be accepted, before turning the tables on the First Minister to explain what the devil she’s going to do about it. Mutely welcoming the diktats of Tory ministers – without a breath of complaint about their democratic legitimacy – seems a curious way for our fearless political reporters to hold the powerful to account.

Worse than that, they treat the UK Government’s legal analysis as gospel. News reports and bulletins are peppered with the bland assertion Holyrood needs Westminster’s say-so to organise an independence poll. These assertions – presented as pure, incontrovertible fact – almost never give the rider that this is open to question, and there are good arguments which suggest this need not be the case.

As a politically minded lawyer, you can’t help but notice that law tends to have a weird effect on folk involved in and reporting politics. Some see it as “just a makey-uppey thing”, just formalities and technicalities, which the robust politician can brush aside. The other reaction – at the other extreme – is to treat law like a holy object to be handled gingerly, pristine and untouched by the grubby business of politics.

Both perspectives, it seems to me, are mistaken. Law doesn’t collapse into politics. It is very rarely party political. But what the law is, is inherently political. The fact that X, or Y or Z happens to be the law is no guarantee of its merit, political legitimacy or even its morality. We need to understand the constitutional debate in this context.

Despite what you often hear, the 2014 referendum wasn’t legally binding. The key question isn’t whether Holyrood has the legislative competence to run an “advisory” plebiscite on independence either. The central question is whether any referendum would fall within the Scottish Parliament’s legislative competence.

Let’s break that down a bit. The Scotland Act is structured around a reserved powers model. Powers which are not reserved are devolved. A Section 30 order isn’t a special licence from Whitehall, as it is often presented. Instead, an order under Section 30 changes the Scotland Act’s list of reserved matters. In 2014, this was used to put beyond doubt Holyrood had the competence to organise the first poll.

If, however, the parliament passes laws which “relate to reserved matters”, the law officers – or indeed, any ordinary punter – is entitled to refer them to the courts for a ruling on their competence. If the courts find that MSPs have exceeded their authority, the offending parts of the legislation will be struck down. The same goes for decisions of Scottish ministers which stray into reserved areas, or which would fly in the face of fundamental rights and freedoms.

So how do the judges decide if a given law is sound or not? The Scotland Act gives the courts a series of tools. They need to ask themselves “what is the object and purpose” of the legislation they’re being asked to review. Section 102 of the Scotland Act also says something else important about how they should approach this task.

When confronted with devolved legislation which could be read as outside of Holyrood’s competence, the Act says the court must read the legislation “as narrowly as is required for it to be within competence, if such a reading is possible”. This isn’t quite a directive to presume all devolved statutes are within Holyrood’s powers, but is a clear steer that, where possible, an interpretation which upholds devolved statutes should be preferred over ones which would result in the courts striking down Holyrood’s legislation willy-nilly.

Applying these principles to the national question produces two competing but compelling lines of legal argument. For the UK Government, you might argue that a second independence referendum “relates to” the reserved matter of “the Union of the Kingdoms of Scotland and England”. The “object and purpose” of a second poll is the breakup of Britain. On this logic, neither the Scottish Parliament nor Scottish ministers have the power to organise any referendum on this question.

But on the other hand, the Scottish Government has its own, I’d argue, equally credible story to tell the bench. As the Bill introduced to Holyrood this week neatly illustrates, “referendums” aren’t reserved matters under the Scotland Act. They’re devolved. And we can look at the question of the “purpose and effect” of the referendum from different angles.

Certainly, the Greens and SNP may organise a second referendum in the hopes of winning it, but one irony of the UK Government’s position is that it is predicated on the idea that a majority of Scots would vote Yes in a second poll. As we learned in 2014, they might not. In a legal sense, all such a referendum would do would be to canvass public opinion. The case is credibly arguable both ways.

So much for the law. The most fundamental arguments are political, principled and democratic. The UK is not Spain. The Scotland Act is not a constitution. Its clauses and passages have been amended, time and again, as politics has changed and political expediency has dictated.

If the Scottish people, in a democratic process, decide to elect a majority of their representatives on a platform that a referendum should be held on the constitutional future, what right do any of these people have to stand in their way?

Agree with it or disagree with it, with more and less grace, for decades, the UK political parties have understood that Scottish independence is a legitimate political aspiration. After 2014, it is now a mainstream aspiration commanding the support of around half of Scots. Snidey lawyering about the Scotland Act won’t change that. “Burnishing your unionist credentials” for the Scottish Tory membership won’t change that. Saying “no” won’t change that.

From Brexit to Labour’s collapse and the mounting mania of the Conservative Party, the Britain of 2014 is dead. The political life of this country has materially altered. Deny it if you like. Cling to the smouldering wreckage if you want to. Fan the flames if they keep you warm in the cold. But no man – and certainly none of the league of gentlemen in contention for the Tory leadership – has the right to fix the boundary to the march of a nation.