The Liberal Democrats have called for a more "honest approach" to crime, with life sentences "meaning life".
Sir Menzies will attack Labour for 'abysmal failure' on crime
Party leader Sir Menzies Campbell said Labour's record in office had been one of "abysmal failure" and that the approach has to be "smarter".
"Tough community work" would be used as an alternative to prison, he said, with those sent to prison given "fixed length sentences" in open court.
Prisoners would also be put to work, with some earnings going to victims.
The fixed term sentences would have minimum and maximum terms announced by a judge in open court.
Offenders would be eligible for parole after the minimum term and granted release on the say-so of a parole board.
Sir Menzies said: "Liberal Democrats believe that sentences should mean what they say.
"Life will mean life: only those that judges believe should stay in prison forever will be given a life sentence.
"And nobody will be released earlier than the minimum term that they are given."
Lib Dem research suggests that less than one in 100 crimes are dealt with in court.
Sir Menzies said: "That means you are twice as likely to buy a winning lottery ticket as you are to be convicted in court of a crime that you have committed."
He added: "And Britain's prison population has topped 80,000 for the first time in our history."
The Conservatives offer "nothing but empty rhetoric", he said.
Sir Menzies also said: "To fight crime effectively, we don't need to get tougher; we need to get smarter.
"A liberal approach to crime is an honest approach to crime. It is based on what works rather than what sounds good.
"It targets the offender rather than the innocent. And it has the courage to engage with the criminal and reform their behaviour."
Sir Menzies promised to divert money earmarked by the government for identity cards into putting more police on the streets.
The Lib Dems would allow people to "take back" town centres, he will say, adding: "It is unacceptable that members of the public fear crime on their streets.
"It is not liberal to tolerate intimidation and disorder. So we will empower members of the public to tackle this problem for themselves."
The Licensing Act would be amended to make it easier to close "problem" pubs and clubs.
He added: "It is only fair that money raised by prisoners in employment should go towards compensating their victims.
"Prisoners shouldn't sit in their cells for 23 hours a day. They ought to be engaged in work that is productive and useful.
"By making prisoners do real work for a real wage, we can also instil a sense of responsibility, enhance their skills and ensure that victims are properly compensated.
"Prisoners will literally pay for their crimes, whilst gaining the skills and experiences needed to dissuade them from further offences."