I am tempted to vote against AV in the forthcoming referendum just to give Nick Clegg a poke in the eye.

After leading students up the garden path on tuition fees, he deserves to get his cumeuppance.

But voting against AV just to humiliate Clegg and destabilise the Lib Dems, while satisfying, would be cutting off my nose to spite my face.

Ed Miliband has got it right.

We need to change.

First-past-the-post works in two party systems. But with more parties, the greater the chance that successful candidates will be elected on a minority, sometimes a small minority, of the votes cast.

Seems to me this raises questions of legitimacy.

Political parties are no longer monolithic, commanding the automatic support of huge sections of the electorate. Party membership is, unfortunately, shrinking everywhere.

And party loyalities, though still strong in many areas, are slowly dissolving as more people are prepared to shop around.

I find the old arguments in favour of first-past-the-post – that it delivers strong government where the manifesto is carried through – less compelling these days.

I spent years watching Party leaders trying to circumvent manifesto commitments.

So when I hear the old foghorn, John Prescott, yelling at Newsnight viewers earlier this week about the importance of the manifesto, I almost switched off.

The days when the manifesto was a reliable guide to what will actually happen have long since gone.

As I tap this out I am thinking of the clear commitment to keep the Royal Mail in public ownership. That didn’t stop the Mandelsons of this world trying to flog it off.

Anyway… back to the point

Preferential voting is no big deal. Labour has used the eliminating ballot in internal party elections - including the selection of Parliamentary candidates – for as long as I can remember.

However, I am disappointed the AV referendum will go ahead without a 40% turnout rule.

I’ve long believed in setting thresholds in referendums and regret there isn’t going to be one.

There are few things bigger than changing the voting system (maybe breaking up the UK is another) and it is at least conceivable this may be decided on a turnout of less than 50%.

But, regardless of the turnout, winning the referendum will be no easy matter.

Two Canadian provinces have tried to change FPtP in recent years. In British Columbia in 2005 and again in 2009 and in Ontario in 2007.

In every case, voters stuck with what they knew and understood, holding on to nurse for fear of something worse.