With all the significance it carries for the country, it shouldn’t be forgotten what a consequential event next week’s vote on the Brexit deal is for the Conservative Party.

The effect of the Brexit deal, or the lack of one, on the economy and people’s livelihoods obviously matters more. But even now, at this late hour, there is still a hope that even if parliament votes against Theresa May’s agreement, there is a chance that opposition parties and conscientious Tories will ensure a chaotic no-deal Brexit can be avoided.

The Tories don’t have any safety net. If as many as 100 of their MPs do decide to vote against the deal because their desire for an even more distant relationship with the EU means they’d prefer no relationship at all, that will have a profound on the party’s identity. The damage could be as great and as long lasting as that felt by the economy as a whole.

The vote on Theresa Mays Brexit deal may be the culmination of the Conservative partys civil war over Europe (Picture: AFP/Getty)

A column appeared in the Times yesterday, written by David Cameron’s speechwriter. Clare Foges wrote some good speeches for the then-Prime Minister, and has written some bizarre things for herself since he left Number 10, but her words yesterday got Conservatives nodding along – particularly Scots. “I read it and agreed with everything it said,” one told me.

“I look at the behaviour of many fellow Tories and feel that the common denominators have dissolved,” Foges wrote of the lost Conservative brand. “Brexit zealotry has led to a reckless disregard for the national interest, a casting aside of much that made this party one of the most successful in history. The certainties that framed the Conservative Party are fast disappearing.”

In examining how next Tuesday’s vote represents a decisive moment in the process that Foges describes, consider the contrasting approach of the two groups the Prime Minister owes her premiership to: the Scottish Tories and the DUP.

When the deal with the DUP was signed, Ruth Davidson didn’t hide her unhappiness at the implications for the Tories’ image on LGBTI rights, and David Mundell tried to strike a tough tone over the £1bn of extra funding for Northern Ireland, but arithmetical realities at Westminster took precedence.

More recently, Davidson and Mundell signed a letter rejecting “any deal that delivers a differentiated settlement for Northern Ireland beyond the differences that already exist”, and letting it be known that they would resign rather than support a deal that did.

David Mundell: No-deal Brexit likely outcome if May deal rejected

It seems they’ve recognised the strategic error of being tied to a group prepared to throw themselves off a cliff. The top two Scottish Tories have stepped back from the precipice, and most of their MPs look set to, as well.

Among the Scottish group of MPs, only Ross Thomson is committed to vote against the Brexit deal. Half of the rest support the Prime Minister, and it wouldn’t come as a surprise if the waverers also fall into line.

Conservative opinion in Scotland isn’t any less eurosceptic than the rest of the country. If they listened to their constituency parties, Scottish Tories would probably be voting against the deal.

But Scottish Tories have respected the foundational logic of Conservatism that went missing the day David Cameron called a referendum on the EU: safety first.

Perhaps their real power as the first Scottish group sent to Westminster in 20 years, rather than being the bloc that was claimed in 2017, is in resisting Tory opinion.

In contrast, the DUP are set to vote against the deal. In making their sole demand that there is no trade barrier in Irish Sea, they are effectively letting it be known that they would accept a no-deal Brexit for the whole UK.

That means they would also be willing to accept a Norway-style Brexit that could be the product of a Labour-SNP pact that might follow a government defeat next week. And yesterday, DUP sources also let it be known to the Times that they could even vote against the Prime Minister in a vote of confidence, triggering a general election and potentially letting Jeremy Corbyn into Downing Street.

I don’t pretend to be an expert on the complex forces that animate the DUP or its supporters, but from the outside, the party appears to be engaged in a demonstration of its ability to say and do anything, by saying and doing anything. Many Tories are bemused at Downing Street’s insistence that their pact with the DUP remains intact.

For their part, Scottish Conservatives know the best way to jeopardise the Union is through a chaotic, no-deal Brexit. Even when senior Scottish Tories claimed “no deal is better than a bad deal” in public, in private they acknowledged that no deal was worse for the integrity of the UK.

“How can we continue to paint the socialists as chaos merchants when the Conservative Party is the architect of the most pointless, damaging own goal in history?” Foges asked at the conclusion of her column yesterday.

“Next time around, voters will be forgiven for seeing the choice between the main parties as one between two destabilising forces wearing different coloured rosettes.”

She was referring to blue and red rosettes, but in Scotland, the same applies with the yellow rosette of the SNP in the frame.

It’s unlikely to be the end of it, but next Tuesday is probably the culmination of the Tory civil war over Europe. The stakes are high, for the country and the party. The more time passes, the more the relative cohesion of the UK politics appears unique in Europe. Where other countries have seen fragmentation and a rise of extremes, Britain’s two main parties have survived because those forces have been contained within them. That could still change.

In the battle for the Conservative Party’s soul – between the path followed by the Scottish Tories versus that of the DUP and its fellow travellers – it’s clear which way leads to safety, and which to greater danger.

Brexit: Tories fear being tarred as '˜chaos merchants' '“ Paris Gourtsoyannis