The US Attorney-General apologised yesterday to the eight lawyers sacked by his department, admitted that his own “mis-statements” about his role in the affair had caused confusion and then pleaded with senators to let him keep his job.

Alberto Gonzales’s appearance in front of a hostile Senate Judiciary Committee was a humiliation both for him personally and for an Administration that is now rocked almost daily by fresh revelations of scandal or incompetence.

On occasions Mr Gonzales appeared to be taken aback by the ferocity of his crossexamination from Republican, as well as Democratic, senators. “These attacks on my integrity have been very painful to me,” he said in his opening statement.

Later, asked if he had considered resignation, he insisted that he could still do the job, adding: “Every day I ask myself that question. The moment I believe I can no longer be effective I will resign as Attorney-General.”

Although US federal lawyers are political appointees who serve at the pleasure of the President, Justice Department officials provoked an outcry earlier this year when they claimed that the reason for sacking eight of them was “performance-related”.

Since then there have been repeated allegations, as well as testimony on Capitol Hill, that the decision was politically motivated after key members of the Administration had attempted to influence specific Justice Department investigations.

There has been widespread incredulity over the White House claims, in response to congressional requests for information, that about five million e-mails, including those sent by Karl Rove, President Bush’s closest adviser, had been lost.

Patrick Leahy, the committee’s Democratic chairman, said: “The Department of Justice is experiencing a crisis of leadership perhaps unrivalled during its 137-year history. There is a growing scandal swirling around the dismissal and replacement of several prosecutors and persistent efforts to undermine and marginalise career lawyers.

“We hear disturbing reports that politics played a role in a growing number of cases. I fear the Justice Department may be losing its way; it should never be reduced to another political arm of the White House.”

Mr Gonzales, a member of President Bush’s diminished inner circle, apologised to the eight fired prosecutors and their families, saying: “They deserve better from me and the Department of Justice.”

But he added: “I firmly believe that nothing improper occurred.” Although he admitted the process should have been “more structured”, the firings “were justified and should stand”.

“It would be improper to remove a US attorney, to interfere with or influence a particular prosecution for partisan political gain,” Mr Gonzales said. “I did not do that. I would never do that.”

Some of his toughest questions yesterday came from Republican senator Arlen Specter, who focused on Mr Gonzales’s contention that he had not been heavily involved in the firings.

“We have to evaluate whether you are really being forthright,” Mr Specter said, adding that Mr Gonzales’s description was “significantly, if not totally, at variance with the facts”.

Mr Gonzales replied: “I should have been more precise when discussing this matter.”

Times Recommends

• Should Knox’s trial even have reached the courtroom?
• 'Was it real?' The US bailout nightmare
• Iranian opposition plays the long game