Tony Blair yesterday signalled that he was ready to give the police more summary powers to deal with alleged offenders as he sided with "the decent law-abiding majority" against the political and legal establishment.

The Prime Minister displayed his frustration with the failure of the criminal justice system to deliver effective remedies to victims by proposing that it should be circumvented.

In a speech intended to provoke a wider public debate about where the balance lay between the civil liberties of suspects and victims, Mr Blair said the system took too long to deliver justice.

He was even prepared to contemplate reforms that risked "rough justice" because the alternative was "rough injustice when neighbourhoods are terrorised by gangs and the system is not capable of protecting them".

Mr Blair - who admitted that he was under siege over law and order - was addressing an invited audience at Bristol University, where he heard one of his Government's senior officials question his whole approach to crime.

Rod Morgan, the head of the Youth Justice Board, said there had been "far too much" legislation which had caused public uncertainty and confusion.

"As a former magistrate, when I speak to the judiciary they say they are confused and are getting mixed and contradictory messages as to what is required of them," Prof Morgan said.

His concerns followed similar criticisms voiced at a recent Downing Street seminar by Ian Loader, an academic criminologist, but carry more force because of Prof Morgan's role in government.

However, Mr Blair made clear that he fully intended to introduce even more laws in this area. He said: "There is a myth that we have legislated 50 times, the problem still exists, ergo we don't need more laws. I disagree. These laws have made a difference.

"This is not the argument of the lynch mob or of people who are indifferent to convicting the innocent. It is simply a reasonable and rational response to a problem that is as much one of modernity as of liberty."

He added: "I know what large numbers of such people believe. They believe that we are on a populist bandwagon; the media whips everyone up into a frenzy, and if only everyone calmed down, the issue would go away.

"But the public are anxious for a perfectly good reason: they think they play fair and play by the rules and they see too many people who don't and getting away with it."

Mr Blair said details of new proposals would be announced in July by John Reid, the Home Secretary, as part of his plans to reform the department.

They are expected to include measures to improve the delivery and administration of justice as well as more powers for the police to hand out interim anti-social behaviour orders and on-the-spot fines without first going to court, though they would have to be given judicial backing later.

In a later question and answer session, Mr Blair said: "It will mean probably a police officer in an area having powers that traditionally could only be exercised by a court.'

He added: "The scale of what we face is such that whatever the theory, in practice, in real everyday street life, it can't be tackled without such powers.

"It is not about choosing hard-line policies over an individual's human rights. It's about which human rights prevail. In making that decision, there is a balance to be struck. I am saying it is time to rebalance the decision in favour of the decent, law-abiding majority who play by the rules and think others should too.'

The prospect of being handed more summary powers was welcomed by Ken Jones, the president of the Association of Chief Police Officers (Acpo).

"We need to restore the ability of cops on the street to enforce the law in an efficient and effective way,' he said. "It's got horribly bureaucratic, formulaic and Byzantine and that's just for cops - never mind victims and witnesses."

Sir Anthony Bottoms, criminology professor at Cambridge University and an adviser to the Prime Minister, said it was "perfectly possible to deal with both the rights of the victim and of the offender".

He added: "My own advice to the Prime Minister, though, was to say, 'Don't put too much emphasis on the criminal justice system.'

Sir Anthony, speaking on BBC radio, said people were concerned about the "quality of life on the streets, the everyday policing, the everyday work of local authority community wardens."

He added: "It is that kind of day-to-day social order that is of more concern to most people than details of the criminal justice system."

David Davis, the shadow home secretary, said: "How can a Prime Minister who has had nine years in office, with some of the largest majorities in history, accuse Parliament of watering down his legislation?'

Nick Clegg, the Liberal Democrat home affairs spokesman, said the speech was "an admission of failure by the Prime Minister'.