Why it’s so hard for Cameron to win

Peter KellnerPresident
April 29, 2015, 3:32 PM UTC

The electoral maths does not favour the Prime Minister and his party

Here’s the bottom line. Labour needs fewer seats than the Conservatives to end up in power after 7th May – the reason involves a mixture of rules and arithmetic.

The rules first. David Cameron will be Prime Minister on 8th May. And probably 9th May. Indeed, he will step down only if and when he decides he can’t win a majority in the House of Commons for a Conservative Queen’s Speech. In that case he will resign as PM and advise the Queen to ask Ed Miliband to form a government.

Now it is theoretically possible that Miliband won’t be able to command a majority either – for example, if the Tories, Lib Dems and SNP decide to vote down his Queen’s Speech. That would provoke a constitutional crisis and, very possibly, an immediate second election. We can be certain that the prospect of such turmoil would terrify the financial markets and appal public opinion.

For that very reason, it won’t happen. The Tories, having acknowledged defeat would themselves face either a leadership election (if Cameron resigns as party leader as well as PM) or a leadership crisis (if he tries to hang on). The party will be in no position to try and thwart Miliband at this early stage. If, in a fit of madness, they announced their intention to try and vote down Miliband’s Queen’s Speech, and so provoke constitutional gridlock, Tory support in the polls would crumble. Rather than travel the road to perdition, they are likely to abstain (as they did in broadly similar circumstances on March 1974). Miliband will secure a majority, and possibly a huge majority.

In short, the immediate question on 8th May will not be whether a majority exists for Labour to govern. It will simply be whether Cameron can construct a majority for his Queen’s Speech. If he can, he will stay as Prime Minister. If he can’t, then Miliband has no need to do a deal with the SNP, Lib Dems or anyone else. Labour will lead the government. Depending on circumstances, Miliband may offer a deal to the Lib Dems, in order to implement progressive policies over a full five-year term; but he has no need to do so in order to get over the immediate hurdle of establishing himself as Prime Minister.

Now to the airithmetic. There are dozens of possibilities, depending on the precise performance of the Lib Dems, SNP and UKIP, as well as Labour and Conservative. Here are three that illustrate the range of outcomes. For each, I assume that the SNP wins 47 seats, the Lib Dems 28, Ukip 3, Plaid Cymru 3, Greens 1 and Ulster parties 18. In other words, suppose that the combined total of Labour and Tory MPs is 550, and that of other parties 100. Within that 100 will probably be five Sinn Fein MPs who never take their seats at Westminster.)

1. Con 300, Lab 250. To win a Queen’s Speech vote, Cameron will need the support of the ten likely Ulster Unionists. If he secures this, then he wins the vote providing the Lib Dems either support him or abstain. If the Lib Dems abstain, then the totals are Con+Ulster Unionists 310, Lab+SNP+Green+Plaid Cymru+SDLP+Ukip 307.

2. Con 290, Lab 260. Now Cameron needs the positive votes of the Lib Dems as well as the Ulster Unionists: Con+Lib Dem+Unionists 328, Lab+SNP+Green+PC+SDLP+Ukip 317

3. Con 280, Lab 270. Cameron can’t do it. Even if he secures the support of Ukip as well as the Lib Dems and Unionists – an improbable alliance – he reaches only 320, while the potential line-up against him is 325.

The conclusion is clear. Unless the numbers of Lib Dems, SNP or Ukip MPs are very differently from those indicated above, the Tories need close to 290 MPs to stay in power, while Labour just needs to get past the 270 mark. That is why the winning posts for the two parties in two week’s time are different, and why Miliband could enter Downing Street even if he leads a slightly smaller contingent of MPs than Cameron.

This article first appeared in Prospect