What counts as a majority?

In all the pre-election discussion, much attention focuses on the number 326. It’s half of 650 (which is the number of seats in the new House of Commons), plus one. And anyone who reaches 326 is therefore guaranteed of a majority in the Commons.

But there’s good reason to be sceptical about 326 being the target number.

For one thing, the election in Thirsk and Malton is not taking place today – because of the death of the UKIP candidate. It is, or should be, a safe Tory seat. But until it actually counts, who knows? (I mean, who knows what it would be like were it be contested in by-election-like conditions, as the difference between a hung parliament and a Conservative government?). As of today, 649 seats are up for grabs.

Then there’s Sinn Fein MPs, who don’t take their seats. At present, there are five of those. If we assume they hold all five seats, and make no gains, that makes 644 seats actually up for grabs. (It’d be one of the ironies of a really close election that Sinn Fein gains would actually be good for David Cameron...)

And then there’s the Speaker and three Deputy Speakers, who don’t vote (except in tied votes). Assuming John Bercow is returned in Buckingham and continues as Speaker. That leaves three Deputy Speakers, two of whom have retired. Assuming the one remaining Deputy Speaker, the Conservative Alan Haselhurst holds his seat and continues in office, that leaves two to be filled. The Conservatives could attempt to argue that both have to be from the ranks of the Opposition (given that there is normally parity across the four, and that both Haselhurst and Bercow represent Conservative seats, albeit formerly in the case of the latter). That effectively reduces the number of seats in play by another one.

That makes 642, rather than 650. And means a majority of 322 would provide David Cameron with a majority, at least until the end of the month. And figure of 323 would mean he had a majority whatever happens in Thirsk.

In practice, on day-to-day business there’s also the fact that the other Northern Irish MPs often have lowish turnouts in Commons votes, which could also bump up his majority by a handful.

These sort of minor details often go unnoticed. But in an election which is going to be this close, every seat could matter.

Professor Philip Cowley