Public confidence in judges has been undermined by the recent spate of media attacks on the judiciary, Lord Chancellor Lord Falconer has told MPs.
Lord Falconer says he is protecting judges' independence
Judges have come under fire after paedophile Craig Sweeney was given a life sentence but told he could seek parole in five years.
Lord Falconer said press criticism had had an impact but he denied there had been rows between ministers and judges.
Sentencing often "bewildered" the public and was under review, he said.
Lord Falconer was giving evidence to the Commons constitutional affairs committee in the wake of the sentencing row.
The Sweeney case, where a three-year-old was abducted and sexually abused by a convicted paedophile, put life sentences in the spotlight.
Home Secretary John Reid said the sentence was too lenient but at the time Lord Falconer said it was the arrangements, not the judge, which were at fault.
On Tuesday, Lord Falconer said neither the government nor the judges thought they had been having rows over the issue.
He refused to say whether he had spoken to Mr Reid about his criticisms.
But he told the MPs: "You can rest assured that both privately and publicly I have taken steps to defend the independence of the judiciary."
He said there had been explicit criticisms of judges from the media.
"That has had an impact on undermining confidence in the judiciary," he said.
He played down newspaper reports suggesting one judge was prepared to resign - saying he knew of no judges who were thinking of quitting.
Lord Falconer admitted the sentencing system was complicated and left people attending court or crime victims "utterly bewildered by what's happening".
"All of us together - the executive, judges and legislature - have got to see how can we improve that," he said.
Lord Falconer singled out some of the areas which had to be the focus of the sentencing review.
Where sentences were automatically cut by a third in return for a guilty plea, there were questions about cases where the criminal was in any case "caught red-handed", he said.
And changes might be needed too in cases where sentences were cut where a guilty plea was a minor issue in relation to the "horror" of the crime.
Lord Falconer said the system was currently too rigid - the result of years of people trying to encourage more guilty pleas by giving more certainty about discounts to sentences.
"That regrettably culminated in a situation where individual judges could not do anything but give a one third discount," he said.