Following the UK Supreme Court ruling on 23rd November 2022, the stated policy of the Scottish Government is to claim that the next Westminster election (likely in 2024) will be a “de facto independence referendum”. This won’t work (for all the reasons stated elsewhere)!
However, what the Supreme Court ruling said was that the right to self determination applied “where a definable group is denied meaningful access to government to pursue their political, economic, social, and cultural development”. This suggests a route that is at least consistent with the ruling and so provides fewer opportunities for the opponents of independence to claim it is illegitimate.
The first crucial aspect of this route is that the platform adopted by the pro-independence candidates in the next Westminster election, as well as demanding a Section 30 order for a new independence referendum, has to be abstentionist: if elected they promise not to take up their seats (and consequently also not to receive their salaries and short monies). If more than 50% of Scottish seats are held by abstentionist candidates then “a definable group is denied meaningful access to government to pursue their political, economic, social, and cultural development”! The Supreme Court upheld that the appropriate forum for discussing the constitution was at Westminster and yet Scots have no representation there. A referendum must be held to resolve this unsustainable position.
If the UK Government denies this, then that is the moment for the Scottish Government to resign, precipitate a new Holyrood election, with candidates standing on the platform of forming an independent government - basically UDI. Note that both of these elections would only require a majority of members elected rather than a majority of the electorate: that’s fine - the demand is for a referendum in which a majority of the electorate is required; if this demand is refused though then no need to fight with one arm tied behind your back.
