AN INDEPENDENCE referendum without the consent of Westminster would not “have any effect on the Union,” the SNP has said.

In a submission to the Supreme Court, the party claim that the holding of a vote would have no more “than a loose or consequential connection with any reserved matter" and that a win for Yes “is not an act of secession.”

The argument comes as the SNP attempt to intervene in the Scottish Government’s indyref2 legal battle. 

Last month, in a surprise move, the party’s ruling national executive committee unanimously agreed to ask for permission to take part in the case. 

The intervention led to speculation that the SNP were unhappy with the even-handed approach of Lord Advocate, Dorothy Bain. 

Roddy Dunlop QC, the Dean of the Faculty of Advocates, suggested there was a risk the party's case could “cut across” the arguments made by the law officer

However, in their submission to the court, drawn up by Claire Mitchell QC and advocate David Welsh, the SNP insist their argument is “additional and complementary to those set out by the Lord Advocate” and is not intended to “detract from” her position.

Although the 1998 Scotland Act explicitly states that the Union is reserved to Westminster, legal academics have, for years, suggested there is some uncertainty around whether or not it is lawful for the Scottish Parliament to hold a vote.

The issue has never been settled definitively by a court.

In her written case, Ms Bain suggested Holyrood staging its own independence referendum would have no legal effect because it would only be "advisory."

She told the court a vote was possible if the justices ignored the wider political implications. 

However, in their application to join the case, the SNP make clear that if voters did back independence it would lead to "a process of negotiation and subsequent legislation" but these "discussions are separate from the referendum and do not inform its purpose.”

The party's submission said that they have long believed that it is unnecessary for Holyrood to require the consent of Westminster to hold an independence referendum.

But for the 2014 vote, it was “politically expedient” to agree to a Section 30 order devolving the necessary powers as “it removed the threat of legal challenge from the process.”

The application goes on to say that “there have been a series of material changes in circumstances since the 2014 independence referendum which collectively justify the Scottish people being asked for their views in relation to Scottish independence again”.

These include Brexit and the “dramatic growth in support” for the SNP and other pro-independence parties.

The SNP also argue that there should be weight attached to their 2021 manifesto which contained an explicit commitment to give the people of Scotland “the right to decide our own future” and “a referendum when the Covid crisis is over to decide whether Scotland should be an independent country.” 

The submission says: “Having secured election to both the United Kingdom Parliament and the Scottish Parliament on a clear manifesto commitment to hold a referendum on independence, the applicant’s position is that it has a duty to the people of Scotland to seek to implement that manifesto commitment in order to place beyond doubt the view of those people… as regards the manner in which they choose to be governed.”

They reference the convention in the House of Lords which stops peers from voting down a manifesto commitment made by the UK government. 

The SNP’s lawyers argue that “the public is entitled to expect that parties (and groupings of parties) which are elected to govern will give effect to their manifesto commitments. It is on that basis that the public cast their votes and it is on that basis that they reasonably expect to be governed in a democracy.”

The SNP, like the Lord Advocate, say that the key to any ruling by the justices will be over the phrase “relates to reserved matters” in the Scotland Act.

Ms Sturgeon’s party say it “should be given a narrow and restricted interpretation… so as not to infringe upon nor render otiose the right of the Scottish people to exercise their right to self-determination.”

They then argue that the vote being proposed by the Scottish Government “does not of itself implement the result or the outcome of that referendum.” 

“That there will be subsequent secondary discussions between the UK and Scottish Governments in the event that the Scottish people indicate their support for Scottish independence does not change that. 

“Those discussions are separate from the referendum and do not inform its purpose.”

The SNP contest that “the purpose of any legislation to hold a consultative referendum on Scottish independence is self-evidently to determine the view of the Scottish people in relation to the question posed. 

“That is an exercise by the Scottish people of their right to self-determination. The implementation of the exercise of that right in the event of a vote in favour of independence would require an Act of the UK Parliament. 

“Whatever the outcome of any such referendum, Scotland would not – and could not as a matter of law – become an independent country by default the day after ‘referendum day’. 

“The referendum itself is not an act of secession; it is not a unilateral declaration of independence.

"A process of negotiation and subsequent legislation would be required to give effect to a referendum outcome in favour of independence.”

The SNP claim the holding of a referendum would have no more “than a loose or consequential connection with any reserved matter in the 1998 Act.” 

“Seeking to test the views of the Scottish people by way of a referendum is perfectly competent and, standing the continued electoral mandate given to the applicant as set out above, it is democratically unthinkable that the people of Scotland would be denied such a right to express their view.”

They argue that “the holding of a consultative referendum does not result in a reduction in the scope of the powers of the UK Parliament and nor does it, of itself, have any effect on the Union.”

They add: “Legislation to enable such a referendum does not, therefore, in the respectful submission of the applicant, relate to the reservation of the Union nor to the Parliament of the United Kingdom.”

The party's Business Convener, Kirsten Oswald said: “The SNP’s application is now with the Supreme Court.

"It is intended to support and complement the arguments for the Bill being within the Scottish Parliament’s competence that are set out in the Lord Advocate’s written case.

“The SNP’s application focuses on the inalienable right of all nations to self-determination which is enshrined in the United Nations charter and argues that the Scotland Act should be interpreted in a way that upholds rather than denies that right. 

“The Bill raises a fundamental issue of democracy - in line with the principle of self-determination, Scotland’s future must be decided by those who live here, not dictated by Westminster politicians."