Nick Clegg has written an article for today's Guardian. In it, he explains why he is not standing for the Liberal Democrat leadership and outlines the purpose of the party.

The strongest piece of the article is when he steps back from the leadership contest and considers the wider picture:

There is much at stake. Not only will the future of the Lib Dems be shaped by the outcome, but also the direction of politics in this country. As David Cameron swiftly morphs into a pale imitation of Tony Blair, the need for a forceful, independent Liberal voice to challenge the two larger parties has never been greater. Who else would have opposed the invasion of Iraq when Labour and the Tories both supported it? Who else would have opposed the expensive and illiberal proposal for ID cards when Labour and the Tories agreed (even though the Tories have now executed a welcome U-turn on the issue)? Who else would have spoken up in defence of the environment before Labour and the Tories decided it was trendy to do so? Who else will campaign against the bossy top-down system of government, barely accountable to parliament or the country at large, which Tory and Labour governments over the years have done so much to defend?

This is a clear attempt to stake out territory for the party, backed up not by promises, gimmicks and PR exercises, but by a record of actions. It is with justifiable pride that Liberal Democrats can talk about the defence of civil liberties, scrutiny of the Iraq war, opposition to ID cards, concern for the environment. For Liberal Democrats, these are matters of principle, not presentation. It is worth pointing out that there is no Conservative, not even supposedly liberal-minded 'Dave' Cameron, who can point to a similar record. Cameron's 'liberalism' is skin-deep, a convenient political stance to take when opposing an authoritarian government.

Liberals must, of course, welcome Cameron's conversion to our cause. His support is gratefully received. Whilst I must confess to a degree of sarcasm in expressing this sentiment, it is not entirely false - the issues at stake are serious ones and any support, from any quarter, is good for the cause of liberty. But to rely on David Cameron as the defender of liberty would be foolish in the extreme. He lacks a record and his Damascene conversion to liberalism points to a very Blairite chameleonic tendency.

For this reason and others, it would be wrong for the Liberal Democrats to play "me too!" to Blair and now Cameron. Leaders should have records behind them, on which they can be judged. Leaders who can change their views to suit the opinion polls and newspaper editors might be good at getting elected, but they are rarely good at running the country, or observing the principles that their supporters elected them to observe.