Love, power, betrayal: the tragic inevitability of Blunkett's demise

When the saga about David Blunkett's private life broke in the political dog days of August, even his many critics in the Labour Party did not imagine it would end in his resignation. Yesterday, as the Home Secretary's survival prospects darkened by the hour at Westminster, the tragic ending for him seemed utterly inevitable.

When the saga about David Blunkett's private life broke in the political dog days of August, even his many critics in the Labour Party did not imagine it would end in his resignation. Yesterday, as the Home Secretary's survival prospects darkened by the hour at Westminster, the tragic ending for him seemed utterly inevitable.

Mr Blunkett started the crisis sparked by his affair with Kimberly Quinn, the married publisher of the conservative magazine The Spectator, with more credit in the bank than most fellow ministers would have enjoyed. Even his critics respected the way the blind boy who grew up in real poverty had fought his way up to one of the great offices of state.

His dramatic rise up the political ladder was followed by a dramatic fall after a saga which at times resembled a Jeffrey Archer novel and at others a Shakespearean tragedy. Mr Blunkett's fate was sealed by his decision to put his desire to have a relationship with Mrs Quinn's two-year-old son, whom he says he fathered, ahead of his political career. He was one politician who really meant it when he talked about putting his family first.

The bitter battle that ensued when Mrs Quinn ended their three-year relationship in August ultimately brought him down. It is not known how the secret of their affair became public in the News of the World a few days after Mrs Quinn told him she was staying with her husband Stephen. Both parties deny disclosing it.

In a reversal of the usual man-woman roles, Mr Blunkett was not married and ­ despite his high-profile post ­ wanted to make the relationship between "the socialist and the socialite" public. He had asked Mrs Quinn to marry him on several occasions; he thought he had found his soul mate for life.

Mrs Quinn, who wanted to keep the affair quiet because of her marriage, may have calculated that Mr Blunkett would put his political career first. She was wrong, as was apparent when the Home Secretary took the dangerous course of fighting back against the media campaign being waged against him by the Quinns. Stephen Quinn admitted that the campaign was designed to influence the High Court's Family Division, which was due to hear an application by Mr Blunkett for access to the two-year-old boy.

The media battle produced what proved to be the killer fact in a raft of allegations against Mr Blunkett's conduct during the affair. On 28 November, The Sunday Telegraph, part of the same group as The Spectator, reported that the Home Secretary had fast-tracked an application by Mrs Quinn's nanny, Leoncia Casalme, for leave to remain in Britain permanently.

A story which the broadcasters and some newspapers, including The Independent, had ignored could no longer be described as a private matter: such a serious allegation was clearly a matter of public interest. A dangerous line had been crossed.

Mr Blunkett denied the charge but the gravity of it forced him to set up an inquiry into it by Sir Alan Budd, a former Treasury adviser. The terms of reference were tightly drawn to exclude other allegations, including claims that Mr Blunkett gave Mrs Quinn rail warrants worth £180 for MPs' spouses and drew his civil servants into the messy end of his relationship.

His stock of credit plummeted sharply after a biography of Mr Blunkett revealed his unflattering views on the performance of cabinet colleagues.

The haemorrhage of support in the Cabinet and among Labour MPs certainly did not help his chances of surviving the storm. The hurdles from Sir Alan's inquiry got higher. By this week, it was becoming clear that Mr Blunkett needed a clean bill of health to carry on.

On Tuesday, the Home Secretary realised he was not going to get one. Sir Alan told him that there had been a fax and an exchange of e-mails between his office and the Immigration and Nationality Directorate on the letter informing the nanny of a possible 12-month delay. Mr Blunkett did not remember it, but he knew that the writing was on the wall.

The previous day, Mr Blunkett was beginning to betray a note of desperation as he started casting around for support in all directions. To the astonishment of Labour MPs, he turned up at their Christmas party, and then burst into a rendition of Fred Astaire's "Pick Yourself Up". Embarrassed looks were exchanged all round and guests, including John Prescott, watched the bizarre spectacle in astonishment.

The left-winger Bob Marshall-Andrews went public with the gossip among Labour MPs on Radio 4's Today programme yesterday and chose devastating language to wield the knife. He said: "One is dealing here with somebody who it appears, certainly to many people in the Commons and the country, is quite seriously unbalanced."

The end came with remarkable speed. At 4pm yesterday, Downing Street was still giving its unswerving support to Mr Blunkett. Half a mile away at the Home Office, however, he failed to turn up for a photo call for a government initiative to tackle knife crime.

At that moment it became obvious at Westminster that Mr Blunkett's cabinet career had entered its final hours. At 6.04pm, his resignation was confirmed.