Not content with ignoring Nicola Sturgeon, Brexit ministers have now taken to trolling her. The Tory Defence Minister's Michael Fallon's “forget it” remark about an independence referendum was an indication of just how seriously the UK government takes the threat of independence right now: which is not very. Theresa May weighed in with her own assessment that the issue was resolved by the 2014 referendum.

According to Fallon, there is “no mandate” for another referendum because the SNP lost seats at the 2016 Holyrood elections and no longer exercises an overall majority. But this is to ludicrously underplay the SNP's success in that proportional election in which it won more seats than all three of the unionist parties - Labour, Tory and Liberal Democrat - combined. Anyway, the SNP has a majority in the Scottish Parliament for a referendum since the Greens are on board, and that is mandate enough.

The trolling continued in Thursday's UK government White Paper outlining the Brexit objectives. It was a sobering statement of Scotland’s place post-EU. It asserts that MSPs in the Scottish Parliament “only have legislative competence – the ability to make law – in devolved policy areas as long as that law is compatible with EU law”. After Brexit, these laws over environment, justice, agriculture etc “will be set here in the UK by democratically elected representatives”. So, EU powers will clearly not pass by default to the Scottish parliament, but to Westminster. The document says there may be some subsequent devolution of “decision making” to the Scottish parliament, but there is nothing specific.

Brexit deprives Scots of their citizenship of the European Union and the protections they have enjoyed for nearly a quarter of a century: the right of free movement and residence in the EU, protection from discrimination on grounds of nationality or religion and the right to live in a clean environment. These guarantees are lost for ever. The UK government says that all the protections on workers rights etc will be translated intact into UK law by the Great Repeal Bill. But this is disingenuous. These rights will only remain so long as the UK government wants them to.

The whole complex web of EU law – thousands of directives and regulations – will be sifted through by Theresa May's ministers and only those that correspond to their narrow-minded vision of Brexit Britain will remain. Or else, why leave the European Union in the first place? The notion that somehow nothing will change after Brexit is almost as naïve as the idea that the European Union will open up access to the single market after Britain leaves the EU. It can't and it won't.

Will Scots lie back and accept this? Who looks after Scottish interests in this legislative transition? The UK Parliament is supine. MPs delivered the fateful vote to trigger Article 50 even before the White Paper been published. It was a capitulation, a wipe out, an act of parliamentary submission to narrow economic nationalism. Labour is hopelessly divided and likely to be out of power for a decade as the UK is changed into a low regulation tax haven.

The vote followed May's 'Deplorables Tour' of America and Turkey in her increasingly desperate attempt to win trading advantages with two of the most protectionist and right wing governments on the planet. Britain is now out of Europe and swooning into the arms of Donald Trump, the most unreliable and ill tempered ally it is possible to imagine. We're trading the European Single Market for the US market, where the watchwords are “buy American; hire American”. Good luck with that. We are to become Trump UK – the fifty first state, with Scotland providing the golf-courses.

The First Minister's appeals for Scotland to remain in the European Single Market have repeatedly been rejected as incompatible with Brexit. Yet, the White Paper recognises that some sectors of the UK economy – essentially cars and financial services – are so important that they will get a privileged access to it, even if this involves payment to the European Union and the acceptance of its rules. That this makes a nonsense of the whole Brexit project seems to be of little concern to May in her determination to buy a special deal for corporate lobbyists.

So, not only have we been taken out of Europe against the will of the Scottish electorate as expressed in the June referendum, but Scotland is deemed to have less clout in the corridors of power than Nissan UK, or Deutsche Bank. The promise by the former Tory Lord Chancellor, and leading Brexit campaigner, Michael Gove, that Scotland could have powers over immigration after Brexit has been forgotten.

Scotland will be severely disadvantaged by Brexit, and not just by the loss of subsidies and citizenship and the restoration of tariffs and non tariff barriers. Under devolved taxation, Holyrood needs a healthy working age population to maintain its tax revenues to pay for public services. This requires inward migration of around 24,000 workers a year, just to maintain stability. Already, firms are finding that Europeans are reluctant to come here because of the uncertainty about their security and status.

This is the most toxic fallout from Brexit: it is creating an image abroad of a xenophobic Britain, an inward looking Little England that has lost all faith in collective decision-making and international solidarity. Scotland has been an outward-looking, European nation since the middle ages and this regression to a fortress Britain is anathema. Hard Brexit is not something anyone could have envisaged back in September 2014 and it more than justifies another referendum, morally if not legally. The Scottish independence referendum was won on a false prospectus: the assumption that Scotland would remain in the EU. Material changes don't come more material than this.

The UK government is confident that Scots will not opt for independence, now or in the future. The decline in oil revenues and poor economic growth means Scotland has nowhere else to go, or so they believe. Moreover, an independent Scotland, after Brexit will have to cope with a “hard border” between Scotland, which is in the EU, and England which is out of it.

But these are not insurmountable problems. The White Paper makes clear that no such hard border will exist between Northern Ireland and the Republic after Brexit, and that is a precedent that could apply to Scotland. And if Scotland's economic future is uncertain, so now is the UK's. There is no longer any status quo for Better Together to claim as the risk-free option. Either way, Brexit or independence - it's a leap in the dark.

One thing is certain: Europe will not cold shoulder an independent Scotland now as it might have in 2014. If Scotland leaves the UK before Brexit is completed, it could retain all the advantages of being in the single market without a hard border with the rest of the UK. This continuity could make Scotland an attractive place not just for skilled workers, but for companies looking for access both to the new UK single market and the European one.

The timing of the referendum is crucial. If Scotland wants to remain, with Ireland, in Europe the referendum needs to take place well before 2019. It will require great courage and confidence on the part of Scots to seize this moment, and it's not clear whether that confidence exists right now. Certainly, there is not an obvious demand for a new referendum in the opinion polls, though support for independence remains as high as it was in 2014. But attitudes can change very rapidly, and if Scots are given a well argued case, they almost certainly can be persuaded.

The UK government will fight like hell to avoid a referendum on independence, however. Having voted for Brexit, MPs are unlikely to vote for Scoxit, and since the constitution is reserved to Westminster, the UK parliament will have to give its assent. But Westminster cannot block a referendum if there is clear evidence of a demand for one. It will be up to the Scottish government to generate that demand.

Scots must be made aware that they’re now in the last chance saloon as far as Europe is concerned. After Brexit is a done deal, Scotland will be locked into a new incorporating Union, and secession will be fiercely resisted by a highly centralised UK state. In the next crucial twelve months every Scottish voter is going to have to ask themselves the unavoidable question: do we stay, or do we go?