Tony Blair's renewed determination to "rebalance the criminal justice system" will result in the acceleration of plans to deal with a new swathe of low-level crime outside the courts and the "normal processes of the law".

The prime minister is looking at a major extension of summary powers for the police and the use of summary justice, even if it means crossing the line "in terms of civil liberties" to tackle communities' fears on law and order.

The changes that Downing Street is to announce next month are expected to build on a little-noticed paper, Doing Law Differently, published by the lord chancellor, Lord Falconer, in April that talked about "re-engineering criminal justice" and argued that many cases heard in court could be better dealt with in other ways.

"Long processes, which at the end treat the offence as minor and quite possibly impose the same penalty as the defendant would have received at the outset, have the effect of sapping public confidence," said Lord Falconer. "There needs to be a more sophisticated response that takes account of the seriousness and the complexity of the case, and identifies an appropriate response."

The lord chancellor said that magistrates courts used to regularly deal on Monday mornings with crimes that had taken place over the weekend. Now it took an average of 153 days for a case to be dealt with from offence to completion. He said returning to the aim of "crime today, court tomorrow" would require identifying which cases would be best handled outside the court process. That process has been going on with the Home Office and the attorney general over the last three months, and as well as antisocial behaviour, ministers think criminal damage, theft and public order offences could be kept out of court.

"If the defendant admits guilt and is willing to make reparation to the victim, accept a fine, pay compensation, go for drug treatment or carry out unpaid work, many of these cases can be diverted out of court and dealt with by the use of fixed penalty notices or conditional cautions," Lod Falconer said.

Ministers are also looking at a swifter, summary way of using conditional cautions - including paid compensation - to deal with those who plead guilty to minor criminal damage, graffiti and similar offences.

The rule of thumb appears to be that where cases handled by magistrates usually get a low-level fine they should be dealt with elsewhere, leaving serious and contested cases to the courts.

Ministers expect a booming number of motoring cases generated by traffic cameras capable of automatic number plate recognition will be dealt with in this way. Even contested cases in this area will not get a physical hearing, with the matter dealt with by correspondence.

Mr Blair explicitly acknowledged last week that to provide more "quick and effective action" in this area meant crossing the line "that most people think of as there in terms of civil liberties".

Critics says that line is based on the notion of "guilty until proven innocent". In this case, the present choice is to accept the fixed penalty notice or spend months arguing the case in the courts.