The Government has been urged to publish the legal advice given to the Prime Minister by the Attorney General before he commented on Andy Coulson's conviction.
Valerie Vaz asked for an urgent debate in the Commons in light of Mr Justice Saunders' criticism of David Cameron and other political leaders for speaking about before all the verdicts had been returned in the hacking trial.
The Prime Minister led the way in what the senior judge described as "open season" on political reaction which saw the Chancellor George Osborne, Labour leader Ed Miliband and others follow suit.
At the time, the jury was still deliberating on two remaining counts against Coulson, 46, of allegedly conspiring with former royal editor Clive Goodman, 56, to commit misconduct in a public office in relation to paying police officers for two royal phone directories. The jury subsequently failed to reach verdicts on the counts.
Ms Vaz told the Commons today: " In light of Mr Justice Saunders' comments in the Coulson trial, could we have an urgent debate to publish the legal advice given by the Attorney General (Dominic Grieve) to the Prime Minister who may have inadvertently placed himself above the law?"
Leader of the House Andrew Lansley stressed successive governments had never published legal advice offered by the attorney general nor commented on it.
He added: "What the Prime Minister said the day before yesterday was not intended in any way to prejudice any aspect of the completion of the trial."
Shadow leader Angela Eagle also grilled him on the comments, which could have caused the £1.7 million trial to collapse in its final days.
Repeating Mr Miliband's question from yesterday's Prime Ministers Questions, she said: "Andy Coulson's conviction this week has raised serious questions about the Prime Minister's judgment.
"He was warned, his staff were warned. Some brave journalists were writing openly about Coulson's behaviour but he carried on anyway and brought a criminal into the heart of No.10.
"Do you agree that the Prime Minister wasn't just ignorant about Andy Coulson but wilfully negligent and d o you support calls for a uniformity of vetting for senior Downing Street advisers?
"Will you ask the Prime Minister to return to the House including telling us whether he was advised by any senior civil servants in No.10 against employing Andy Coulson?"
Mr Lansley said Mr Cameron had got the answer "absolutely right" in his response to Mr Miliband.
He continued: "If you look back very clearly at the evidence that was taken and the conclusions reached by Lord Justice Leveson, he made it very clear the Prime Minister received those assurances and acted on the basis of those assurances at the time.
"If he had known then what we know now it would have been very different. And he has made clear he gave Andy Coulson a second chance and he regrets that he did that because it turned out to be a misjudgment.
"The evidence given on that by Gus O'Donnell was very clear, it was a matter determined by civil servants and rightly so in terms of identifying where there is any risk."
Backbenchers, including Labour's Steve McCabe (Selly Oak), also returned to the subject.
He asked for a debate on how Coulson got access to "highly sensitive" information without proper security vetting, adding: "Don't the public have a right to know just how widespread this despicable practice is across Government?"
Mr Lansley replied: "It is not that there was no security vetting, it's that developed vetting had not taken place, which is a substantially different process."