2014. Scotland votes against independence. Scotland potentially losing EU membership a key plank of the ‘No’ campaign.
2015. Scotland votes in 56 out of a potential 59 SNP MPs to Westminster in a first past the post voting system (50% vote share). Tory party gets a majority due to English seats with a 37% vote share. They will implement a referendum on EU membership as stated in their manifesto.
2016 (May). The SNP win 46.5% of the constituency vote giving them 59 seats (First past the post) and 41.7% of the regional vote giving them an extra 4 seats (D’Hondt method). This makes them a minority government, however with the Scottish Green Party there is a pro-independence majority.
(Important note: In the SNP manifesto it stated that if the Scotland votes to stay in the EU but, as a whole, the UK votes to leave this will be ground for the SNP calling a 2nd independence referendum.)
Pre-EU ref 2016. SNP try to get David Cameron, Prime Minister at the time, to agree that the UK will only leave the EU if all four constituent nations vote to leave. This is dismissed. It is a point in the campaign that a vote to Leave the EU might jeopardize the UK & lead to renewed calls for a Scottish independence referendum.
2016 (June). England and Wales vote to leave the EU. Scotland and Northern Ireland vote to remain. The Leave vote wins.
Post-EU ref 2016. David Cameron resigns, Theresa May takes over as Prime Minister. The SNP try to work out a situation where it can remain in the EU but England & Wales leaves. This is dismissed. The Tory party begin to make it seem like a ‘hard Brexit’ will occur. The SNP suggests Scotland staying in the single-market so it can retain the free movement of people. This is dismissed. Westminster does not work with any of the devolved parliaments, leaving them in the dark about Brexit plans. The Tory party begins to make noises about their being no post-EU deal at all.
2017. Nicola Sturgeon, the First Minister of Scotland and leader of the SNP, after seeing that there is no way Scotland can remain in the EU and potentially even the single market begins to implement a part of the manifesto in which her government were elected in on.
The Tory government: