Carryfast:
Which can only be confirmation what I’ve said a Socialist Party masquerading as Nationalists.
But you make it sound so underhand, when really the voters well-understand the the nature of these parties. Both the SNP and Sinn Fein have undergone evolution over their lifetimes, but as I say the defining feature of their supporters is not an ideology of nationalism (in any sense you understand it), but as mere anti-Westminster parties. Plaid Cymru is the same. They are all antibodies to what has been the predominantly right-wing politics of England, and their shared cultural heritage has allowed that resistance to crystallise around supposedly nationalist parties, but the “nationalism” doesn’t really go much deeper than that.
With the possible exception of Sinn Fein, it is probably going too far to say they are “socialist” parties, but there is a tinge of “socialism in one country” to all of them - their demands for home rule and devolved powers is mainly so that they can implement a more left-wing agenda than that of the Tory-dominated British government, and to provide political structures and a platform to fight back against the Tories.
When what they really mean is that they only recognise democracy that is to the advantage of Socialism and hide under the banner of Nationalism and National sovereignty and secession when it suits them to remove themselves from any agenda that they percieve as going against Socialism.
You’re on the right track but I don’t think you have it quite right. All of these regional parties contain (or did once contain) fundamentalists who are(/were) hard-line “nationalists”. But they’ve never had substantial electoral support or political prominence on that basis. What they have morphed into is left-wing parties, who rattle the sabre of secession whenever that left-of-Tory agenda is threatened or stymied - not purely as a bluff, but as a genuine threat that they are not going to continue participating in a union governed by the right-wing tendencies of the Home counties (which is really the main rump of Tory support nowadays - left-wing parties have a stonking margin over the Tories in all cities including London, in the North generally, in Wales, in Scotland, and in Northern Ireland).
While expecting everyone else to kow tow to any type of perceived Socialist majority which they can gerrymander by selectively imposing foreign Federal rule on the country when it suits them and then taking advantage of secession when it doesn’t.
The truth is that the country overall is more left-wing than it is right-wing, and like I say when it is broken down geographically, all regions except the “South” of England (basically, the area beneath a line drawn from the Wash to the Severn, excluding London) are decisively left-wing by significant margins.
If there was a system in GB of proportional representation rather than constituencies, Labour and the SNP combined would have outdone the Tories marginally in seats in 2017, then there would be the LibDems with another 8% of seats (and they are generally considered to be to the left of the Tories, even if not by much), and then another 7% of seats would be represented by minor parties that are, on the whole, left-wing splinter parties.