David Mundell is the Parliamentary Under-Secretary of State for Scotland and the MP for Dumfriesshire, Clydesdale and Tweeddale.

The SNP will enjoy its moment in the sun this weekend, as it meets for its final conference before the independence referendum. For
Nationalists gathering in the Granite City, it will be a giddy moment. SNP activists have spent their political lives dreaming of the chance
to remove Scotland from the United Kingdom.

Many will never have thought they’d get the chance. Yet it is now less than six months before Scotland goes to the polls. It will be a straight choice; Yes or No. In or out.

Mr Salmond should enjoy the rapturous applause of the faithful while it lasts, however. Because – as the conference is likely to underline
– the debate we have been having in Scotland on independence has pushed his party onto the wrong side of a clear dividing line in Scottish politics: between those on our side who want to continue Scotland’s devolution journey, and those who would end it.

With few allies, the SNP has been forced to join up with Greens and a few radical socialists as it seeks to advance its case. It has exposed the party as part of a rigid, fundamentalist grouping which – these days – seems strangely at odds with the way most people in Scotland feel.

How different that all looks compared with the SNP’s early days in power. Wind back to 2007 when the SNP first won office at Holyrood, squeezing home by a single seat. The SNP’s manifesto of that year pledged a referendum on independence by 2010. But fully aware of the unpopularity of independence, Mr Salmond exploited his parliamentary weakness and prevaricated.

The referendum was delayed, then postponed, then cancelled altogether. Instead, with artful vagueness, the First Minister committed himself merely to acting “in the Scottish national interest”. Independence was parked. The benefits of devolution were lauded. The SNP set about trying to entrench itself in power.

This deliberate attempt to downplay independence and reassure people was a success (and was seen as such by the party’s “gradualists”, who stood in opposition to the party’s “fundies”, or fundamentalists, who viewed devolution as a Unionist cul-de-sac).

Ironically, however, it was the party’s election success in 2011, when the SNP won an overall majority at Holyrood, which exposed the limitations of these tactical games. That election gave the party a clear shot at the independence referendum they had been promising for so long. And with the UK Government accepting the SNP’s mandate and agreeing to all of the SNP’s demands on timing, wording and franchise, it ensured that the SNP had to campaign for what it says it wants – separation.

Since been given this opportunity, what we’ve seen over the last few months is that the SNP has been pushed away from the reassuring pro-devolution tone which won it popularity, and into a divisive anti-devolution position which simply doesn’t reflect the settled will of people in Scotland. Gone are the party’s popular and conciliatory words from 2007 and 2011 about making devolution work. Now we are told on a weekly basis that “only” separation is enough; that we “need” to split off to prosper.

This strident fundamentalist tone reached its peak last month when Deputy First Minister Nicola Sturgeon airily dismissed plans by Scotland’s three pro-UK parties to further improve devolution. All, she declared, fell short of what Scotland needed. This was bizarre for two reasons: first, because new powers contained in the 2012 Scotland Act, passed by this UK Government, have not even come into force yet. Second, because many of the further proposals being worked up by the three pro-UK parties which Ms Sturgeon brushed aside had not, at the time of her comments, even been published (and, in the case of the Conservatives, still haven’t – Lord Strathclyde’s Commission will report back later in May).

In other words, the campaign has seen the SNP’s mask slipping. We have all begun to see that no proof, no evidence, amd no proposal will ever persuade the ideologues in the SNP that independence is not the solution to everything in Scotland. And we have all seen that the SNP doesn’t believe in devolution at all; as witnessed by the way the party, in government, has centralised massively to Edinburgh, and away from Scotland’s communities. What has been exposed is the party’s sole reason for existing: its ideological obsession with Scottish independence. Or, put it another way: the party’s inner-fundie has come out.

This is important for two reasons.

Firstly, if “only the powers of independence will do”, as Nicola Sturgeon says, it begs the question: if Scotland votes No, why will voters trust the SNP again with a devolved system of government which it says doesn’t work?

Secondly, with the SNP campaigning relentlessly for their own obsession with independence, the other pro-UK parties can be seen as the occupants of the sensible centre-ground on the Scottish constitution. It marks a major strategic shift in Scottish politics. Previously, it was the SNP which successfully colonised this vital middle ground. Now, on the constitution, the party is out of step with mainstream opinion.

A strong Scottish Parliament within a stable and secure United Kingdom is what the Scottish people want. This weekend will present another opportunity for people to see that the SNP want something else: to rip the United Kingdom apart for their own ideological reasons.