THE constitutional debate has become a “full-blown crisis of democracy”, the SNP’s Westminster leader will argue in a major speech today.

Stephen Flynn will speak at the Institute for Government’s conference on Tuesday, urging Unionists to avoid a “just say ‘No’ to democracy strategy”.

The SNP will hold a special conference in March where party members will hash out plans to fight either a Westminster or Holyrood election as a de facto referendum on independence.

Nicola Sturgeon has previously said she wants to fight the next UK General Election as a de facto referendum on independence – an option recently backed by Flynn.

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An alternative option will be to use the next Scottish Parliament election in 2026 for this purpose.

It remains unclear whether a pro-Yes majority of votes would count as the basis to begin negotiations for independence – or if it would simply bolster calls for a second referendum.

Flynn, who became the party’s Westminster group leader in December, will give a keynote speech at the institute’s conference in London.

He will say: “In a functioning democracy, the UK Government would have accepted that democratic vote by the people of Scotland and agreed to a referendum.

“Instead, Westminster has turned the UK constitutional debate into a full-blown crisis of democracy.”

The Aberdeen South MP will continue: “Having campaigned for No in 2014, it appears the word No is literally all the Westminster parties have left.

“But a ‘Just Say No to democracy’ strategy is doomed to fail. Not only is it driving up support for independence, but it’s fatally undermining any remaining case for Westminster control.

“No one is asking Westminster to say Yes to independence but moderate Unionists know they need to release themselves from the dead end of denying democracy – or they will do more to make the case for independence than any Scottish Government could ever do.”

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In response to Flynn’s comments, Conservative MSP Donald Cameron said: “The SNP have shunned democracy ever since Scots voted to keep the UK together in 2014.

“Stephen Flynn’s comments are an insult to the millions of Scots who chose to remain as part of the UK – in what nationalists claimed would be a once-in-a-generation vote.

“Yet Stephen Flynn and his colleagues insist on ignoring this and then playing the grievance card.

“Amid the current global cost-of-living crisis and with Scotland’s NHS on its knees, the SNP’s obsession with pushing for independence is the wrong priority at the worst possible time.”