The window of opportunity is closing to pass new laws addressing the legacy of the Northern Ireland conflict within a year, victims said.
Time could run out if a consultation is not launched before the end of this year, the Commissioner for Victims and Survivors added.
Northern Ireland Secretary James Brokenshire has been urged to act to ensure stalled mechanisms to deal with the legacy of the Troubles are finally established.
Victims and Survivors Commissioner Judith Thompson said: "We are at a critical stage and time is running out to meet the parliamentary legislative timetable in 2018.
"Consultation documents must be issued by the end of this year or an important window of opportunity will be lost.
"Victims and survivors cannot wait any longer."
She said next year will be a very busy one for Parliament with Brexit legislation.
"The consequence for victims and survivors of further delay could mean some of them will die and others will continue to suffer before they get access to effective investigations and information that some of them so desperately need."
Proposals signed-off in the 2014 Stormont House Agreement - including a new independent investigatory unit, a truth recovery body and an oral archive - are still on ice due to a small number of outstanding political disputes.
Mr Brokenshire is planning a public consultation exercise on the framework in a bid to move on from the impasse.
The Commissioner for Victim and Survivors and members of the Victims and Survivors Forum called upon the Secretary of State to show political leadership by issuing consultation documents.
The Commissioner and the Victims and Survivors Forum has concluded a series of meetings with the leaders of Stormont's five main political parties.
They challenged Mr Brokenshire to stick to his commitment to move ahead with consultations in the absence of an Executive.