This isolated minister had to go

There was an air of inevitability about the resignation of David Blunkett from the moment he lost the support of his Cabinet colleagues. The revelation that he had made critical and dismissive remarks about some of his fellow ministers meant that, at a time when he needed the support of his colleagues more than ever, he found himself dangerously isolated. But, in the end, what pushed Mr Blunkett over the precipice was the investigation of a respected economist. Sir Alan Budd, asked to conduct an inquiry into allegations that the Home Secretary had abused his political position to fast-track the visa application for the nanny of his former lover, gave the Home Secretary the bad news on Tuesday. It turns out that Mr Blunkett, despite his denials, did indeed communicate with the Immigration and Nationality Directorate to push through the visa. Once this fact emerged, Mr Blunkett's fate was sealed.

Sir Alan's report will probably not be presented until early next week, but it is already clear that Mr Blunkett abused his public position. As Home Secretary, Mr Blunkett had a special responsibility for immigration and the issuing of visas. When his lover, Kimberly Quinn, asked him to help get her Filipina nanny a residency visa, he should have declined to get involved. If ministers give special treatment to their family or acquaintances, it fundamentally undermines our democracy. It is a corruption of public office. By the act of resigning, Mr Blunkett has shown he has no defence against this charge.

It is a shame that the career of a man who has succeeded in the face of such profound disadvantages throughout his life ­ not least the loss of his sight as a child ­ has taken such a course. It is not just the abuse of office that will be such a disappointment to Mr Blunkett's supporters, but the manner of his departure. The revelations about the Home Secretary's sex life which have been appearing in the press have turned what was initially seen as a rather tragic case of a broken relationship into something of a farce.

Mr Blunkett maintains that none of this would have happened had he not taken a brave decision to pursue his paternity rights over Mrs Quinn's child, of whom he believes he is the father. There is an element of truth in this. The initial allegations that Mr Blunkett fast-tracked the visa came as part of a concerted campaign to discredit him and put pressure on him to withdraw his paternity claims. But even his most loyal supporters surely have to admit that the Home Secretary has done himself no favours in recent weeks. By first refusing to talk about his private life and then doing just that in a radio interview, he made his private agony a public issue and showed his judgement to be deeply flawed.

This newspaper has never been very sympathetic to David Blunkett. But not because of they way he chose to conduct his private life. Our objection has been to his profound illiberalism. In many respects Mr Blunkett has been a disastrous Home Secretary. He has made moves to abolish the right to trial by jury ­ one of our oldest liberties. In the teeth of much opposition from his Cabinet colleagues, he was pushing through an ID card scheme that would have been an unwarranted constraint on our freedom. But perhaps Mr Blunkett's most dangerous legacy has been his anti-terror legislation. The right to intern suspects without trial has given us a frightening glimpse of a world in which our freedoms are sacrificed in the name of our safety.

Mr Blunkett has also been responsible for a shameful debasement of public discourse about those from less fortunate lands. He consciously echoed the xenophobic tone of the authoritarian press when he framed policy on asylum-seekers or talked about economic immigrants. In Mr Blunkett's mind, foreigners were rarely people who had something to offer Britain. Instead they were something to be resisted and deported if possible. That stance won plaudits from The Sun and the Daily Mail, which will lament his passing, but it also did great damage to Britain's reputation as a country of justice and tolerance.

But Mr Blunkett has undeniably been an immensely important figure in Tony Blair's government, both as Home Secretary and in his role before 2001 as Education Secretary. His resignation is a damaging blow for the Prime Minister and leaves a hole at the heart of Mr Blair's Cabinet. That such a key minister should be forced to resign so close to a general election gives the impression of crisis at the heart of government. There is also the question mark over what will happen to the anti-terror legislation Mr Blunkett had prepared. Will it be implemented by Mr Clarke, who is considered to be more liberal?

The Government must use Mr Blunkett's departure as an opportunity for a new start. It ought to ditch the headline-chasing tactics favoured by Mr Blunkett and embrace a more socially tolerant agenda. Mr Blunkett's resignation is no doubt a personal tragedy for him, but it could mean a new lease of life for liberalism in this country.