Most of us are interested in politics because we believe in something, whether this is liberty, free markets or personal responsibility. We see our involvement in politics as putting forward something positive: we seek to create a change and we quite sincerely think this will be for the better.

But, needless to say, we do not live in an ideal world and most of us are going to be disappointed if we insist on holding out for the right sort of change. So for most of us, as we face up to the next four weeks of electioneering in the UK, we will be faced with an imperfect choice, between parties which might not be offering us much of what we want. The Labour Party seems hell-bent on continuing with its ruinous policy of tax and spend, whilst the Conservatives insist on keeping any plans they might have close to their collective chest; as for the Liberal Democrats, they seem to be relishing the publicity of an election whilst hoping that no one takes them too seriously and asks them a difficult question.

But if we cannot find a positive reason to vote this does not mean that we should abstain. My 17-year-old daughter tells me that she sees no point in voting and that her friends feel just like her: all politicians are the same and none of them want to do anything anyway. My response to her, in the most unpatronising voice I can manage, is to tell her that a government has as much power and influence over us whether 35% or 50% of the public vote for it: it can still pass laws, raise taxes and make our lives worse.

What we can do is to consider which party will do the least damage and which party would take us furthest away from where we wish to go. So I shall definitely be voting and will make my decision for entirely negative reasons. This, in our imperfect world, is the only principled thing to do.