Nick Clegg: Sorry no longer the hardest word

It is, they say, the hardest word. Nevertheless, after more than two years of resisting, Nick Clegg has decided that it is time he said it, said it clearly and said it directly.

In a party political broadcast filmed at his home the Liberal Democrat leader speaks directly to camera and with real intensity about a decision which he believes has become a weight around his and his party's ankles - the decision to break his word by first signing, then breaking a pledge to vote against increases in student tuition fees.

"There's no easy way to say this: We made a pledge, we didn't stick to it - and for that I am sorry. When you've made a mistake you should apologise.

"But more importantly - most important of all - you've got to learn from your mistakes. And that's what we will do.

"I will never again make a pledge unless as a party we are absolutely clear about how we can keep it"

The Lib Dem leader says that it was "a mistake" to make a pledge that couldn't be delivered when there was no money to pay for it and when his party was only likely to be in power in coalition with Labour or the Conservatives - both of whom were committed to increase tuition fees.

He is equally clear, though, that he is not apologising for the policy he backed in government which, he believes, will come to be seen as fair.

This is quite a contrast to what he said to me in an interview in December 2010.

"To govern is to choose particularly when there is not very much money and we have chosen and I am not going to apologise for this for one minute."

This broadcast has been released a few days before the start of his party's annual conference. Nick Clegg knows that it will provoke disbelief, anger and ridicule from many but hopes it will start to enable him to win back trust from some of those who once believed in him.

I'm told that many close to Nick Clegg reminded him of the old dictum - never apologise, never explain - but he decided that saying sorry was his best hope of persuading voters to listen to the "right things" his party stands for instead of only remembering what he now acknowledges was a mistake.