Let’s assume, as I did in previous pieces here and here, that no party will win a majority on May 7th, and that all the post-election pressure will be for a minority government with an arrangement with one or more other parties that falls short of coalition. On current polls the Liberal Democrats will not get enough seats for it to be practicable for us to enter coalition, and the third largest party will be the SNP who have made it clear they will not enter any coalition but will seek a looser agreement with Labour.

None of this may happen but the probability seems high enough to discuss how it might work. I am also assuming that, for reasons I’ve also set out previously here, the Fixed-term Parliaments Act will make it very difficult for anyone to force an early second election. In spite of this (or perhaps with some level of ignorance) both Labour and Conservative MPs seem to favour minority government. All this could mean that a minority government may not only be the short term outcome, but could last for some time – perhaps a full five years.

The position of the SNP is interesting, to say the least. Nicola Sturgeon’s speech at the SNP conference is worth reading in full. Her pledges to vote down a Conservative Queen’s Speech are just rhetoric – if it’s going to be voted down, it’s not going to take place. If the post-election negotiations result in a deal between Labour and the SNP which means that between them (or with a few added friends) they can muster a majority for Miliband, Cameron will have to resign. The Queen is not going to invite anyone to form a Government unless and until her advisers tell her they can survive a vote of confidence – and that the Gracious Speech will not be kicked out in the lobbies.

On the other hand Sturgeon came closer than before to saying that SNP MPs would take more interest in “English matters”. She talked about budget matters including welfare reform. She talked about working practices and the living wage. She talked again about the NHS across the UK. But she also talked a lot about the constitutional issues – “all that is deeply undemocratic and unfair about the Westminster notion of democracy”. She appealed to “ordinary people across these islands who feel just as let down by that out of touch Westminster system as we do” and to “people of progressive opinion all across the UK”. She pointed out that the SNP know how to make minority government work. You don’t have to like her or her party to realise that this is the kind of thing that Liberals and Liberal Democrats have been saying for decades.

But if Sturgeon and her party are serious about all this they are going to have to think hard about their role at Westminster. If they hold most Scottish seats and continue to abstain on “English matters” they will fall into the very trap that the Tories are trying to set with Hague and Cameron’s “English votes for English laws” nonsense, handing the English Tories a majority on “English” legislation. And when the Commons send Bills to the Lords, with or without SNP help, they will go to a Chamber without a single SNP member (their own choice) where the very clear balance of power will be held by the hundred-plus Liberal Democrats. If Sturgeon wants the SNP to be treated seriously in helping to sort out Westminster – “to shake up and reform that discredited and outdated system” on behalf of “the needs and demands of those ordinary people, wherever they are in the United Kingdom” – she’ll have to find ways for her party to take part and perhaps also do deals with us. If Labour have any sense they’ll only shake hands on a deal if SNP MPs promise to pull their weight on matters affecting the rest of the UK.