Sorry seems to be the easiest word

Nick Clegg has apologised in a party political broadcast ahead of his party conference over row regarding the hike in tuition fees - a source of immense reputational damage to him and his party.  He is sorry for a mistake but the 'mistake' he is sorry for is for pledging never to raise university tuition fees ahead of the last General Election, not for actually pushing them up once in government.  I don't think this will wash.