So, after an excruciatingly long delay, we are finally to be allowed to have our say about who we wish to govern us. Commonsense would suggest that we are overdue for a change of government. But given the increasing disenchantment with politics generally, an electoral system currently weighted against the Tories and the relatively small differences in real policy proposals between the parties, anything is possible. Attitudes (not even hard policies) on a few key issues may well prove decisive.

The Conservatives seem to have hit on one topic which resonates with people: the latest National Insurance increase. Here's another suggestion: if they were to break ranks on the apparent shared belief among political elites that present policies to limit greenhouse gas emissions are both necessary and effective, they are likely to tap into a deep vein of scepticism about the greening of politics among the mass of voters.

Now, given the carefully crafted image as a party deeply committed to environmental issues (which includes a puzzingly distate for both nuclear power and airport expansion) any volte face at this stage would be both difficult and surprising. However, the enthusiasms of the Cameroons are not shared by all Tory MPs (although, to be fair, the next batch of candidates might find them more to their liking). The man and woman in the street, meanwhile, are unconvinced that the planet is facing a crisis, while seeing green taxation as just a politically-correct way to separate them from a higher proportion of their earnings. Any party which shows it is willing to question the orthodoxy and think again might get a useful electoral boost.

Martin Livermore is the director of The Scientific Alliance.