The SNP has blown British politics apart – and the UK must now change if it is to survive

I sat in the media area of the Glasgow count, 50 metres from the Scottish National Party (SNP) crowd. From 2.30am, every few minutes, they would first cheer another SNP win and then gasp at the huge swing in their favour. They hoped it would happen. Maybe they even expected it. The polls suggested they would win big. Yet the expectation is not the same as the actual result. This was something else: a sense of real excitement at something remarkable happening in Scottish – and British – politics, again and again, in quick succession.

So in the hours and days to come, much will be said about the implications for UK government and the future of the union. Right now, we should take a step back to think about how big this SNP win is. In Scotland, Labour has dominated the number of seats in Westminster for decades, and the last and only time that the SNP reached double figures was in October 1974. Even after the SNP became the biggest party in the Scottish parliament in 2007, it secured only six (20%) MPs in 2010. Now it has virtually wiped the floor with the other parties on the back of record-breaking swings in its favour, and there is no such thing as a “safe seat” in Scotland (for anyone else).

Opponents of the SNP have been talking about the perils of voting for the party and the likelihood of a second independence referendum. Instead we should be talking about the SNP’s near-complete dominance of Scottish elections despite losing the first referendum. The SNP is described by its competitors as a one-aim party. It is time to put that image to bed once and for all, and to recognise its skill as a major political party.

What will he do this time?

But what of that wider constitutional question? A gaping hole has been blown in the current incarnation of that UK. When 55% voted No to Scottish independence in September 2014, David Cameron immediately linked further constitutional change in Scotland to reform in England. He made the result about two distinct audiences in Scotland and England.

To protect the union, he needs to do the same again after regaining power in Westminster: celebrating victory on the back of votes in England but respecting the Scottish result in a meaningful way. He should not simply dismiss the SNP as a soon-to-be ineffective party in opposition, sitting next to the defeated Labour party. Otherwise, he may as well kiss goodbye to the union, since the SNP is no ordinary opposition party. Let’s consider three main choices.

The temptation for the Conservatives will be to select what it sees as the safe option, to argue that Scotland voted No; the party kept its promise to hold the Smith Commission on further devolution; and that all parties signed up to its recommendations, which will be put into legislation as soon as possible.

If the party sticks with Smith, the new devolved settlement will seem dated before it is implemented. It currently has no other source of legitimacy in Scotland. This will look like just another short-term fix – another shot at constitutional tinkering after a stitch up between the UK political parties. It will not satisfy a population that just ensured an almost clean sweep of SNP seats.

A settlement that makes sense

The Conservatives could go further and give the SNP more of what it thinks it wants – such as greater movement towards fiscal autonomy (it will almost certainly not offer a second referendum, and nor should the SNP take it). Yet if it already came up with a new devolved settlement a few months ago, this response will suffer the same image problem: a quick fix by a party with minimal credibility in Scotland.

Finally the Tories could do what they promised for England: take a step back to consider the future of the union and key parts within it. To get around the legitimacy problem, it needs to propose to the SNP something like a new constitutional convention, set up with meaningful representation across civil society, to ensure that its recommendations have weight and do not seem like yet another sticking plaster produced after inadequate deliberation and consultation.

It also needs to ensure that, if more powers are devolved to Scotland, the settlement actually makes sense and can be understood easily by most people in the UK. Otherwise, David Cameron may quickly finds himself in a situation where it looks like he no longer cares about the union and Scotland’s place within it. That could take us perilously close to the abyss.