THE SNP's leader at Westminster will today accuse the Conservatives of turning the constitutional debate into a “full blown crisis of democracy”.

Stephen Flynn will speak at the Institute for Government’s conference urging opponents of a second independence referendum to avoid a “just say ‘No’ to democracy strategy”.

His party is to hold a special conference in March where members will choose the exact offering to Scottish voters at the next election and whether to back the First Minister's plan to use it as a de facto independence referendum.

Nicola Sturgeon has said she wants to fight the next general election on the single issue of independence, while an alternative option would be to use the next Scottish Parliament election in 2026 for this purpose.

The wording of the party's draft resolution, drawn up last weekend by the party's national executive committee, and which will go before SNP members in March also includes the possibility using the next Westminster poll not as a de facto independence referendum but to gain a new mandate for an agreed vote, as the SNP have done in previous elections since the Brexit vote in 2016.

Mr 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 also criticise Labour for opposing a second independence referendum.

He 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.”

Scottish Conservative shadow constitution secretary Donald Cameron MSP hit back and 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.

 “Rather than stirring up division with this self-serving nonsense, the SNP should concentrate on the issues that really matter to Scottish people.”

Mr Flynn said on Sunday using the next general election as a de facto independence referendum is the "best option" for his party in the absence of an agreed referendum.

Last year, following his election as SNP Westminster leader, he appeared to raise doubts about the plan saying there were a number of options.

Polling expert Mark Diffley said at the weekend that most recent polls have shown a small majority in favour of independence with the "big picture" suggesting the country was split around 50-50 for either side.

However, he added that polls have have also shown that most voters think using the next GE as a de facto referendum is not a good idea.

"The issue..of the de facto referendum and which election, whether it's a general election or a Holyrood election that the party chooses, is really important," he said.

"Because the majority of voters don't think using the next general election as the de facto referendum is a good idea. So in terms of the next steps towards a referendum or how you fight the next election this is going to be a really really important decision the party has to make."

Scottish Labour was approached for comment.