THERESA May will be delivered “an ultimatum” at this week’s SNP conference to keep Scotland in the EU or face an imminent second independence referendum.

A resolution to be debated on Friday calls for the country to prepare for a new plebiscite on sovereignty if its EU membership is not safeguarded once the UK leaves.

The resolution was put down by Toni Giugliano, of the party’s Edinburgh Western branch, and also welcomes the result that 62 per cent of voters in Scotland backed remaining in the bloc.

“My resolution is basically an ultimatum which tells Theresa May ‘this is your last chance’. If you do not allow Scotland to remain in the EU then your days as Prime Minister for the whole of the UK are numbered,” Giugliano told The National. “The Prime Minister is closing off the idea of Scotland being able to stay part of the European Union within the UK so that leaves us with very little option but to move forward towards a second independence referendum – which would have to take place before the UK leaves the EU and ahead of the European Parliament elections in May 2019.”

He added: “The mandate for a second referendum is the overwhelming vote by the Scottish people on 23 June in favour of staying in the EU. Scotland voted to remain and that vote needs to be respected.” By supporting a second independence referendum in early 2019 Giugliano has put the prospect of an imminent ballot back on the table after a number of senior figures in the party argued against such an approach. Last month, the ex-Scottish Government minister Alex Neil said Nicola Sturgeon should rule out another independence referendum in the near future. He would prefer to see Scotland getting significantly more powers, for instance over immigration, under new Brexit arrangements.

His former colleague ex Justice Secretary Kenny MacAskill has also warned against a “headlong rush” towards another referendum to “appease” party members, while depute leadership candidates Tommy Sheppard and Alyn Smith have also spoken of a need for a cautious approach. In contrast, however, former First Minister Alex Salmond last month forecast the second independence referendum would take place in the autumn of 2018.

May drew fury on the opening day of the Tory conference last week when she described supporters of Scottish independence as “divisive nationalists” and insisted there will be “no opt-out from Brexit” for any part of the UK.

“The negotiations between the United Kingdom and the European Union are the responsibility of the Government and nobody else, she said. “Because we voted in the referendum as one United Kingdom, we will negotiate as one United Kingdom, and we will leave the European Union as one United Kingdom. There is no opt-out from Brexit. And I will never allow divisive nationalists to undermine the precious union between the four nations of our United Kingdom.”

Her words were seized upon in Scotland with critics pointing out how the leave vote was driven by British nationalism and came after weeks of debate about what possible options could be left for Scotland to remain in both the EU and the UK.

Ahead of the Tory conference May said she would trigger Article 50 – beginning the two-year legal process of leaving the EU by March next year. Around 3000 delegates and 500 journalists are to attend the SNP annual conference starting in Glasgow tomorrow. The first item on the agenda at the SECC will be the result of the depute leadership contest. Sheppard and Smith are two of the four candidates. Angus Robertson, the party’s Westminster leader and Chris McEleny, the leader of the SNP group on Inverclyde Council are also standing.

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