THERESA MAY has warned Nicola Sturgeon to expect disagreements ahead of their first face-to-face meeting to discuss plans to keep Scotland in the EU single market.

Speaking before a joint ministerial committee (JMC) on Brexit today, the Prime Minister made it clear the devolved administrations would not have a decisive role in the exit process.

She said last week’s Supreme Court ruling on the triggering of Article 50 had put it “beyond doubt” that relations with Brussels would ultimately be determined by the UK government.

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She previously said she would not trigger Brexit until a “UK approach” had been agreed.

Today’s meeting comes after the First Minister warned a second independence referendum was “all but inevitable” if Mrs May rejects the SNP proposal for a bespoke Scottish Brexit.

However a new Panelbase poll for the Sunday Times found just 27 per cent of Scots want a second referendum before Brexit, compared to 51 per cent opposed.

Ms Sturgeon will raise her proposal at the JMC in Cardiff, which will also be attended by the Welsh Labour First Minister, Carwyn Jones, who wants a soft Brexit deal for Wales.

Mrs May said: “We will not agree on everything, but that doesn't mean we will shy away from the necessary conversations and I hope we will have further constructive discussions today.

"We have also had the Supreme Court judgment which made clear beyond doubt that relations with the EU are a matter for the UK Government and UK Parliament.

Read more: Ministers accused of treating Holyrood 'with contempt' over missing Bills

“We should not forget that that means MPs representing every community in the UK will be fully involved in the passage of Article 50 through Parliament."

Ms Sturgeon said: “It is becoming clearer with every day that passes that the UK Government is determined to pursue a hard Brexit and I am determined to do all I can to protect Scotland from the devastating impact that would have.

"We have set out a range of propositions to keep Scotland in the single market. I hope the discussion on this will be meaningful, but the process has been deeply disappointing so far.

“Time is running out for the Prime Minister to demonstrate that she is going to uphold the commitment she made to me shortly after taking office that Scotland will be fully involved in discussions to develop an agreed UK approach and listen to alternative proposals."

Sinn Fein leader Michelle O'Neill said: "It is clear that Tory Government is seeking to impose Brexit against the will of the people in the north and of the people of Scotland.

“The Tory Government have effectively set aside the democratic process to pursue their own narrow political agenda. We need all of those opposed to Brexit to stand together.”

Mr Jones called for "open and frank discussions" about the UK's post-Brexit future.

Read more: Ministers accused of treating Holyrood 'with contempt' over missing Bills

He said: “While we know that the UK will leave the EU we don't yet know how that will happen or what form our relationship with the EU will look like beyond that point."

The meeting will also be attended by Brexit minister Michael Russell, UK Brexit Secretary David Davis and the Secretaries of State for Scotland, Wales and Northern Ireland.

At an event in London today, Scottish LibDem leader Willie Rennie will liken Ms Sturgeon to the boy who cried wolf because of her repeated threats to call a second referendum.

The Scottish Parliament’s European Committee yesterday asked Mr Davis to appear before it for the third time, after previous snubs in July and December.

SNP convenor Joan McAlpine said it was essential MSPs heard directly from him Davis about the UK Government’s position and raised concerns before Brexit talks begin in March.