Senior police officers have said they are worried about plans to allow paramilitary fugitives to return to NI without serving a prison sentence.
People suspected of being involved in terrorism could return
The first hearing in the committee stage of the Northern Ireland (Offences Bill) will take place on Tuesday.
The plan covers up to 150 people wanted for crimes committed before 1998.
The Superintendents' Association vice-president, Wesley Wilson, said if fugitives did not have to appear in court would damage public confidence.
"A victim and a witness will have to appear in one of these courts - and if they didn't answer a subpoena from the court they would be liable to fines or imprisonment," Chief Superintendent Wilson said.
"How fair is that to the victims of these crimes when the potential offenders don't even have to appear?"
On Monday, SDLP leader Mark Durkan said the law was "badly flawed".
He was speaking after meeting Irish Prime Minister Bertie Ahern.
"They (the British government) are intent on covering up the past with the OTR legislation," he said.
SDLP leader Mark Durkan raised his concerns with Mr Ahern
Those covered under the legislation would have their cases heard by a special tribunal, and if found guilty, would be freed on licence without having to go to jail.
The government and Sinn Fein argue that it clears up "an anomaly" left by the release of those already in jail after the 1998 Good Friday Agreement.
The proposed law would set up a two-stage process. First a "certification officer" would decide if someone was eligible for the scheme.
This could be a paramilitary on-the-run, someone living in Northern Ireland who is charged with an offence before 1998 or a member of the security forces accused of an offence committed when they were combating terrorism.
The case would then go to a special tribunal, consisting of a retired judge sitting without a jury. The tribunal would have all the normal powers of the Crown Court but the accused would not have to appear for their trial.
If found guilty they would have a criminal record but would be freed on licence. They would have to provide fingerprints and DNA samples to be granted their licence.
The scheme will be temporary but a precise cut-off period is not specified in the bill - instead its expiry is linked to the lifetime of the chief constable's historic cases review team, which is looking at unsolved murders during the Troubles.