There are now so many red lines laid down during the UK general election that forming a coalition is going to resemble a scene from Mission Impossible. SNP won’t support the Tories, UKIP won’t support Labour, Sinn Féin won’t support (or oppose) anyone,… Most of this is just electioneering. Even the one party that’s keeping options reasonably open – the LibDems – is giving mixed messages probably in the hope it can save a few seats by appealing to Tory or Labour supporters that a vote for them in key marginals could help keep Labour or the Tories out of power.

Labour on the other hand has firmly ruled out ANY deal with the SNP. Again this is electioneering. It’s simultaneously hoping that it can convince Scottish voters that a vote for Labour is the only way to ditch the Tories, and English voters that a vote for Labour won’t damage the Union. 

The British are new to the politics of coalition, and it shows. They’re so firmly socialised in majoritarian politics that they are willing to bash any possible future coalition partners, leaving hostages to fortune all over the electoral battlefield. There’s a (perhaps fake) moral outrage at the idea that the second and third largest parties representing a majority of voters could team up to deny the largest party the opportunity to govern. It is somehow anti-democratic, even if the largest party only commands the support of a third of the voters. All parties are coalitions of different groups and multi-party politics makes this explicit. Normal parliamentary democracies can only function with parties willing to make compromises. The red-lines can be blurred when the arithmetic demands it. We in Ireland know that ‘core values’ are abandoned if power demands it.

The maths is important. Sometimes it gives a small party immense power when it can choose between two desperate prime ministerial hopefuls. The SNP won’t be able to do this. It can’t support a Tory government. But is it really plausible that Miliband would refuse a deal with an ideologically similar party if it is his only chance to become prime minister?

Of course he won’t. It’s an electoral strategy. But as an electoral strategy it might not work. It’s designed (in part) to save votes in Scotland, and (in other part) to stave off attacks that Miliband is willing to compromise the Union for power.

It is pretty insulting to the people of Scotland to suggest that the SNP is persona non grata. The SNP is hardly the Taliban. It represents a lot of people in the UK, who presumably are entitled to a say in the governing of their country. This insult might just drive Scottish voters further away from Labour. The strategy might also over-estimate the desire of Labour voters south of the border to hold on to Scotland. They might want to but are perhaps more interested in issues such as inequality, protecting welfare and public services. Miliband has adopted the Conservative narrative about the SNP rather than weaved one of his own.

If Miliband and Labour really want to save the union AND deliver its preferred policies for its English voters they should invite the SNP into coalition, and not just a so-called ‘confidence and supply’ arrangement. Why? Because government damages parties and especially small parties.

The SNP has an amazing brand. It is simultaneously in government and an expression of the anti-establishment. Supporting the SNP is an act of rebellion, but a pretty safe one. It can do this because it is in government but not fully in control. Where it doesn’t do all it promised it can blame Tory cuts, and continue offering the dream of freedom.

Another ten years of this and the SNP could easily lead Scotland out of the union. For this reason I’d imagine a returned Conservative-led government is the SNP’s most preferred outcome.

Inviting the SNP into coalition removes its ability to blame the government in London. SNP ministers will be blamed for making compromises and for the odd policy failure. They won’t be able to advance their independence agenda much (Miliband can refuse a referendum on the grounds that they just had one), and SNP support will begin to wane. The doctrine of collective responsibility is important here. The SNP must publicly support anything at didn’t want to bring down the government for, and it can’t really advertise its unhappiness – not too much anyway.

If Miliband refuses to deal with the SNP he continues the insult to the Scots, and can only increase the demand for independence. It might force an immediate election on the UK. One that would benefit the Tories. If he only deals with the party at arms-length (a confidence and supply arrangement) the SNP will be able to make a great deal of all the victories it gets, and be seen to force Miliband to compromise in countless eleventh hour negotiations.

Refusing to deal with the SNP is bad politics for now and for later. It’s too late to do anything about this before polling, but one has to hope that Miliband isn’t too stubborn to see it’s not in his interest to keep this up beyond that.