Peaceful civil movements and protests far more common than referendums

But common sense suggests that his warning that Westminster will never grant another referendum on the subject has a ring of truth.

After all, why would it? Bitter experience would suggest to the Unionist parties that such a vote would certainly be against what they perceive to be their best interests.

When David Cameron gave the go-ahead for the first independence referendum to take place, he was confident that he could appear to be magnanimous to a resurgent SNP without risking a significant vote for Yes.

The reality was very different.

Support for independence rose from around 27% to 45%, and there were indications that there was room for it to grow still further.

Next year will mark the 10-year anniversary of the referendum and during that decade, polls have shown independence support increasing, decreasing and more often remaining at around the same level. There is certainly no sign of the collapse in support predicted after a No vote by those wanting the Union to continue.

Why on earth would either the Tories or the Labour Party agree to a second independence referendum when there are now serious indications that Yes could win?

READ MORE: What does Scotland's first AI chatbot think of Scottish Labour and Anas Sarwar?

Uppermost of these indications are consistent poll results showing that the vast majority of younger people support independence. As each successive generation reaches voting age, support for Yes at the ballot box grows. There is nothing to suggest this will be any less true in the future.

Even worse is the example of Brexit.

When Cameron agreed to give the UK a say in its continued membership of the EU, there was no serious prediction that the electors would vote to leave. Nevertheless, the UK majority did just that.

Referendums have been shown to be unpredictable. A second independence referendum would be an undeniable risk for Westminster. What on earth does it have to gain from taking that risk?

Certainly not the destruction of support for independence or for the SNP, if the experience of 2014 is anything to go by. The 2015 UK General Election saw the SNP win all but three of the 59 Scottish seats and about 50% of the popular vote – the largest share for any political party in 60 years.

Today, despite the serious problems the party have faced in recent times, polls suggest the SNP are still the most popular party in Scotland among voters in UK and the Scottish general elections. Even if a second indyref still failed to win a majority for independence – and that is a very big “if”, considering demographic changes – it could still boost the SNP vote. Labour and Conservative politicians would not want to do anything that would make that result more likely.

So why are those parties so desperate to keep Scotland within the fold? It’s not as if they have any real chance of securing power in any election in the foreseeable future and yet they seem irredeemably set against waving Scottish voters goodbye.

Well, the first reason is the incontestable fact that Scotland contributes more financially to the Union than it takes out.

This was particularly true during the oil boom of the 1970s and 80s, when oil companies enjoyed massive profits and the stagnant UK economy was more or less rescued by Scotland’s natural resources.

Unionist politicians certainly recognised the potential of the oil windfall to drive up support for independence, which at that time was nowhere near today’s level.

For evidence, look no further than the McCrone Report of 1974 which examined oil’s role in the economic argument for independence – a chronic surplus in an independent Scotland “to a quite embarrassing degree’’ – and was promptly kept secret for more than 30 years until freedom of information laws came into effect in 2005.

READ MORE: 'Insulting' Gaelic mistakes in Barratt's Inverness street signs

The oil boom may have been consigned to history but oil was still worth an estimated £8.8 billion to Scotland’s economy as recently as 2019. Environmental concerns will drastically curtail oil drilling in future but that doesn’t mean Scotland will no longer make a huge contribution to the UK economy.

In March, Labour leader Keir Starmer popped up to pledge to use Scotland’s resources to turn the UK into a “clean energy superpower”.

Nice of him to tell us his plans, even if he doesn’t feel the need to ask us first.

Although this makes it easy to see why Tomkins thinks it impossible to imagine Westminster “allowing” another independence referendum, it doesn’t, as he insisted in his article earlier this week in The Herald, entirely rule out indyref2 altogether.

It is possible, for instance, that Labour could find themselves in need of SNP support to form a government after the next UK General Election and could – despite recent denials – do a deal agreeing to indyref2 in return for that support.

That’s still a problematic outcome. The SNP would come under pressure to support Labour – even without that indyref2 commitment – on the grounds that failure to do so would keep the Tories in power and who wants that?

Nevertheless, it’s impossible to predict with certainty the result of any Labour-SNP negotiations.

It’s also possible that SNP MPs could wrest from Westminster the powers to call an independence referendum which were recently confirmed to lie in London by the Supreme Court, although that’s certainly a log shot.

But even if Tomkins is correct, a block on indyref2 does not kill stone dead independence hopes, or the prospect of independence support reaching a level undeniably representing the much-lauded “settled will of the Scottish people”.

Those who believe in devolution rather than independence itself must be considering the way a Westminster block on not just a referendum but on Holyrood-approved legislation on gender recognition and the bottle return scheme can in any sense be described as democratic.

It’s true that the anti-democratic argument against the Westminster blocks has yet to really land with the electorate. This is partly because Westminster has chosen its targets well. Opposition to Holyrood-approved trans rights includes some prominent SNP members – mistakenly, in my view, but that’s a debate which does not take away from the fact that the legislation was passed by a majority of Scottish MSPs and by MSPs of every party.

The argument put forward by some SNP members that Westminster should somehow be thanked for stepping in to save us from the mistakes of the Scottish Parliament seems incompatible with a belief in independence.

Similarly, dissatisfaction with the bottle return scheme seems widespread enough within the business community to prevent an outcry at Westminster’s interference.

Nevertheless, the fact remains that Westminster’s actions represent an affront to devolution and to democracy. The silence of Scottish Labour and the Scottish Tories is nothing short of a disgrace and will surely come to be recognised as such even by those yet to be convinced of the benefits of independence.

Another problem was highlighted this week by an episode of the BBC’s Debate Night programme, when an audience member slammed the SNP for “not delivering” for the people of Scotland. Yet, when she listed the failures as poverty, hunger and the cost of living crisis, they were, without exception, caused by the policies of Westminster.

It is true that the SNP can – and do – divert money supposed to be spent on devolved matters to mitigate the crushing effects of Westminster decisions, including the bedroom tax and cuts in benefits.

The impossibility to mitigate EVERYTHING does not mean everything is the SNP’s fault. It’s only right that blame is laid squarely where it is due.

READ MORE: Is Finland's 'worthless' energy Scotland's hope - or a warning?

It’s time that argument and the democratic argument were made more powerfully to encourage the public to understand what is actually happening within this country.

We can gain our independence by growing support for its benefits. Very few countries have achieved their independence through referendums. Peaceful civil movements and protests are far more common, even if they involve mass demonstrations, civil disobedience and the mobilisation of public support.

The SNP’s upcoming independence convention has, for some reason, limited itself to discussing ways of holding a legal referendum.

That may be the “gold standard” but it’s not the only standard. There will have to be, at some stage, consideration of alternative ways to achieve independence – and it’s surely better to do this sooner rather than later.