The Home Secretary rejected calls today for a judicial inquiry into why the radical Islamic cleric Abu Hamza was not brought to justice sooner.
Charles Clarke said he could not see "any merit" in the type of inquiry demanded by the Tories - and urged them to reverse their opposition to anti-terror measures.
Mr Clarke said on BBC Radio 4's Today programme that Hamza's conviction was "really good news" for the justice system because it would help stem the "lack of confidence" which led to delays.
And he rejected suggestions that there had been any deliberate policy of leaving the cleric on the streets.
Hamza, 47, was jailed for seven years at the Old Bailey on Tuesday after being convicted of a string of race hate and terror charges.
Mr Clarke's comments came as one of his predecessors claimed the security services failed to act for fear of provoking a race crisis.
Former home secretary David Blunkett said the Metropolitan Police, MI5 and the Crown Prosecution Service dismissed claims that he was a danger and did not consider him to be a sufficiently significant threat.
Mr Clarke said it was a "lack of confidence" in the ability to secure a conviction that was behind the length of time taken to bring Hamza to trial.
And he promised to learn lessons.
"I don't think there was any decision taken that said 'let's keep him in circulation'. The issue was one of: was there confidence a conviction could be secured?
"I am delighted we have got the conviction, but the lesson I draw is that firstly we have to continue to strengthen the law as we have been, secondly, that we have to improve our investigative capacity so the evidence is able to be put in court in the most effective way, and thirdly, we need a ... determination to secure the convictions.
"The fact that Abu Hamza was convicted is really good news for the whole of the system because what it says is we can get convictions in this area."
Asked about calls from shadow home secretary David Davis for a judge to be appointed to look into the case, he said: "I don't see any merit in that.
"I don't think it's a judicial inquiry that is the issue. The issue is to make sure we give confidence on convictions."
The Opposition could do that by backing moves to outlaw the glorification of terrorism "rather than, as they have thus far, voting to try and weaken it".
Ministers will try to reverse a House of Lords move to scrap that element of new terror laws when legislation returns to the Commons next week.
Mr Blunkett told The Sun that the agencies told him when he was home secretary that he was exaggerating the threat and that to close the Finsbury Park Mosque, where Hamza preached in north London, would be "a massive over-reaction".
It emerged yesterday that evidence of Hamza's alleged involvement in terrorism was submitted to the Crown Prosecution Service (CPS) almost seven years ago.
Scotland Yard first sent a file to the CPS in March 1999 and then again in June 2003, but on each occasion the material was judged to be "clearly insufficient" to support criminal charges.
It was not until Scotland Yard submitted a third file in June 2004, following Hamza's arrest on an extradition warrant from the United States, that the CPS decided to prosecute.Reuse content