The Liberal Democrats have called for violent offenders to be jailed.

On the first day of the party's Brighton conference, its leadership has signalled a need to get tough on violent crime while cutting the number of people jailed for minor offences.

The Lib Dem home affairs spokesman, Simon Hughes, has used a key justice in the community debate to overhaul policies on sentencing and punishment.

And he signalled a strong change in tone - stressing a "crackdown" on violent offenders rather than his party's traditional emphasis on civil liberties.

"Assaults are always unacceptable. There are always reasons but never excuses. Violence is unacceptable, whether it is a street mugger or a terrorist bomber," Hughes told delegates.

"If an individual commits a violent offence then he must expect a custodial sentence."

Hughes argues that David Blunkett's tough crime initiatives have led to too many people being sent behind bars for minor offences.

And he called for a "presumption of imprisonment" for serious offenders.

"There are very clear messages about violent crime being our number one priority and people not going to prison for things that aren't violent and emptying prisons of people who shouldn't be there," Hughes said.

"Cheque fraud may be wrong, but it is not in the same league as stabbing somebody."

The Bermondsey MP told the party faithful that "we have become an extremely impatient, intolerant and violent society".

"It is time for Liberal Democrats to prioritise policies and campaigning against violence."

"A presumption of imprisonment must extend to death or serious injury caused by reckless driving, to those who peddle hard drugs or child pornography, and to those who interfere with the course of justice."

The home affairs spokesman admitted the tougher talk was a bid both to keep pace with the government's agenda and to avoid knee jerk law and order responses.

"We know there's a criminal justice bill waiting the other side of the Queen's Speech. We know that it will be about sentencing and punishment and to be honest we have not updated our positions, nor have we taken clear positions," he said.

"The government has too often been guilty of making policy on the hoof. We need principled not populist policies."

The party will also decide today whether to back the home secretary's proposals to remove juries from complex fraud trials and plans to abolish the double jeopardy rule.

Opposition to disclosure plans to make past convictions known to juries will remain in the Lib Dem manifesto.

Hughes also called for the victims of crime - or their families in the case of murder trials - to be allowed to address the bench and have their views considered alongside the mitigating pleas of the defendant.

The Lib Dems are backing the creation of new "Ministry of Justice".

"We need a Ministry of Justice, not more proposals for injustice. It is time we had a Home Office of order, not a Home Office in disorder," said Hughes.