Blunkett ousted

The embattled Home Secretary had always denied abusing his position to help Kimberley Quinn - with whom he had a three-year affair - keep Leoncia Casalme in Britain indefinitely.

But he was forced to accept the game was up after his own inquiry uncovered evidence that his office urged the application be considered with "no favours, but slightly quicker".

Mr Blunkett continued to deny any wrongdoing and blamed his downfall on the bitter row with Mrs Quinn that followed his decision to fight for access to the son he believed he fathered.

But, in a statement, he said: "Whether or not I asked for any action to be taken is irrelevant to the inference that can be drawn.

"Given I have no recollection of issuing instructions to deal with the application, but only to continuing the elimination of the backlog in general, the easy thing would be to hide behind my officials.

"I will not do such a thing. In no way is my office or any individual within the department to blame for what happened."

The resignation - following three weeks of growing political pressure - deprives Tony Blair of a key lieutenant and friend, only five months before the likely General Election.

And it is also a personal humiliation for the Prime Minister, who had insisted the inquiry by Whitehall mandarin Sir Alan Budd would clear Mr Blunkett.

Bookmaker William Hill immediately cut the odds on a Conservative election victory from 4/1 to 7/2, and lengthened Labour's odds from 1/7 to 1/6.

The tipping point for Mr Blunkett was when he was told by Sir Alan, on Tuesday night, of the electronic paper trail between the Home Office and Immigration and Nationality Directorate (IND).

But, even before that, his position had been undermined by his scathing comments about his Cabinet colleagues, revealed in a biography published this week.

The criticisms sapped initial backing for Mr Blunkett on the Labour benches, a loss of support laid bare when Deputy Prime Minister John Prescott branded him arrogant.

Claims yesterday that Sir Alan had widened his inquiry to cover a visa Miss Casalme obtained to visit her sister in Austria, for Christmas in 2002, did further damage.

Maverick Labour backbencher Bob Marshall-Andrews then launched a ferocious onslaught, describing the Home Secretary as "quite seriously unbalanced".

At Prime Minister's Questions, it was clear Mr Blunkett had become a figure of fun for the Tories when their leader, Michael Howard, tossed a copy of the biography across the despatch box.

The Home Office had said Mr Blunkett did nothing more than check the nanny's visa application for factual errors. But, despite being told it might take a year, she received it in 19 days.

The fatal fax and emails sent to the IND followed the letter to Miss Casalme informing her of this 12-month delay.

Mr Blunkett said the key issue when he set up the Budd inquiry, on November 28, had always been "whether I used my public office for private benefit".

He said: "Everything I have said in the past few weeks about this application I have believed to be true, based on my own recollections and those of others, despite the frenzy of allegations made in the media against me.

"I have always been honest about my recollection of events. But any perception of this application being speeded up requires me to take responsibility."

Shadow Home Secretary David Davis said: "I am very sorry to see David Blunkett go, but it was the right thing to do under the circumstances. He obviously made a serious error."

After his resignation was announced, a clearly emotional Mr Blunkett made clear, in TV interviews, his bitterness at the fight with his former lover over access to their child.

He said the issue of why the visa application had been granted so quickly would not have been raised if he had not decided he could not walk away from the child.

He said: "I misunderstood what we had. I misunderstood that someone could do this, not just to me, but to the little one as well."

Talking about his affair becoming public, he said: "I am mortified that that was done, and I'm very sorry.

"I'm not even angry, I'm just terribly hurt."

Admitting to inevitable depression to come, Mr Blunkett said that was "absolutely nothing compared to the joy of being - in the future - able to grow and work alongside that little lad".

In a letter, Mr Blair said: "You have been a truly outstanding Cabinet Minister as both Home Secretary and Secretary of State for Education and Employment. You have made real and lasting change to Britain."

The Prime Minister moved quickly to plug the gap by shifting Education Secretary Charles Clarke to the Home Office. Rising star Ruth Kelly, a Cabinet Office Minister, will replace Mr Clarke.