David Cameron’s PPE tutor said very early on in his career that he was the brightest student he ever taught. Right now he needs it, as he weighs up the pros and cons of the TV debates. He has plainly done some serious calculations, resulting in the feeling that the positives of pulling out of the TV debates outweigh the negatives.

These events, which completely dominated the previous election, are at the moment planned for April, with two debates containing seven party leaders and the final one, on April 30th, seven days before the election, with just David Cameron and Ed Miliband. But Cameron has essentially pulled out of all of them. First, he has said that he won’t take part in a debate in the last month before the election and now he has indicated to the Broadcasters that he will only take part in a debate with the other six leaders originally in the debate (Labour, Lib Dem,Green, SNP, Plaid Cymru and UKIP) plus Nigel Dodds, the leader of the DUP in the Commons.

That event, which would be 90 minutes long, and effectively mean each leader would have a grand total of 11 minutes speaking time each, would be a farce. Given one ‘debate’, they are going to be desperate to get out their manifesto lines and key phrases and will just end up talking AT each other instead of TO each other. More importantly, whilst there will no doubt be some attacks on David Cameron from the more leaning parties, there will no doubt be more attacks on Labour from the Greens and SNP, who need to denude support for Labour in order to win the seats they are after. This is the first part of the calculation that Cameron has made, that any damage that can be done to him in a debate can also be done to Ed Miliband and Labour.

The second part of the calculation is the avoidance of a head-to-head debate with Ed Miliband. The Conservatives’ campaign relies a lot on painting Miliband as hopeless, potentially incompetent and the harbinger of chaos. But in a debate he could shine, and this is not just because he can easily beat the low expectations of him. When you are the incumbent in a political race your opponent can make hay simply by pointing out any negative consequences of something you have done and then insisting that they would have done something different from you. They don’t have to say exactly what that something is, and it can be pie in the sky fiscally irresponsible claptrap if he wants, but it will still hit home.

So, Cameron has everything to lose and nothing to gain from the debates, and so he is happy to be called a ‘chicken’ if they want to, because the loss of votes from a bad debate would be as bad as..as bad as…well, as bad as the loss of votes that the Conservatives think they suffered from the debates in 2010. Chicken is not the best word for Cameron actually, many have been pointing out that he is in fact a beaver, an animal that tends to put logs in the middle of a river to stop it moving. The debates have stopped moving, and it may actually be good for the substance of this election campaign, if not the style.