The Conservative government announced plans Wednesday to end the "two-for-one" credit judges often grant convicted criminals for time spent in pre-trial custody.

Justice Minister Rob Nicholson told reporters he expects the proposed legislation to be passed as quickly as possible, noting it has "widespread support."

"We've had urgings from people across this country, provincial attorneys general, groups that would like to see this move (forward), and if this new-found interest from the opposition parties to fight crime in this country is sincere, I want to see this move as quickly as possible," Nicholson said in Ottawa.

The actual legislation is expected to be tabled on Friday.

The two-for-one credit system aims to compensate for so-called "dead time" criminals spend in overcrowded detention centres that do not have rehabilitation programs or many of the amenities of long-term prison housing.

Critics who want the credit to end argue that some prisoners abuse the system by trying to stretch their pre-trial time to cut their time behind bars later.

Nicholson said the proposal would put an end to that practice, and speed up the administration of justice.

"I think this will have the effect of unclogging the courts. I think individuals or their solicitors will not find it to their advantage to have continuous delays or adjournments and so I think this will help move the process forward," he said.

CTV's Roger Smith, reporting from Ottawa, said Wednesday that the Tory legislation will likely have the support of the Liberals.

NDP members also say they will also support the legislation, but indicate they want exceptions made for those being housed in the worst jails.

Prominent lawyers protest

But many lawyers have slammed the proposed legislation.

Clayton Ruby, one of Canada's leading defence lawyers, called Canadian detention centres "hellholes" and "a humiliation."

Ruby said the holding centres are extremely overcrowded and prisoners are waiting much too long for trial.

"The rule was a good rule developed by the courts to alleviate the hardships of what we are doing to (those awaiting trial)," he told CTV News.

Ruby said the real solution is to ensure a speedy trial.

"To do that we have to provide more facilities... more judges, more courts," he said. "(But) Mr. Nicholson is not providing a penny for that."

Irvin Waller, founding director of the Institute for the Prevention of Crime at the University of Ottawa, said the legislation is just another example of politicians being tough on criminals and not on crime.

"We don't see here a federal-provincial plan to really reduce the number of victims, we just see tinkering with one small part of the system," Waller told CTV's Canada AM on Wednesday.

If passed, Waller said he expects to see offenders serving longer sentences and more people behind bars.

"That means that we will be paying more of our taxes for after-the-fact solutions to crime instead of investing in the things that would reduce the number of gang-related homicides, the number of women assaulted, the number of robberies," he said.

The two-for-one system came under fire recently when the father of a kidnapping victim expressed his anger when his son's kidnappers had their sentences reduced by six years due to the two-for-one credit.

Robert McMynn's son, Graham, then 24, was abducted at gunpoint in April 2006 and spent eight terrifying days in captivity before being rescued from a Surrey, B.C. home.

Still, the two-for-one credit is not a requirement. For example, the judge in the case of convicted terrorist Momin Khawaja did not give out a two-for-one credit.

But Canada's criminal code says that judges may take pre-trial custody into account and that discretion has become a near-standard practice, backed up by support from various appeal courts.

The government legislation would take away the judge's discretion, but some believe that longer sentences given out under the bill could be subject to a Charter of Rights challenge.

CTV legal analyst Steven Skurka called the legislation a "huge mistake."

"If there is a problem, and I don't accept that there is one, the answer is to pour more money into the justice system and to get in-custody trials on sooner," Skurka said.

He said the legislation would put huge demands on the justice system.

"I don't think this has been thought through at all," he said.

"It sounds like it's been decided on anecdotes rather than empirical studies."

With a report from CTV's Roger Smith