The UK government's proposals for tackling Troubles legacy cases in Northern Ireland have been criticised as "unilateral and unhelpful".
In a scathing report, MPs from the Northern Ireland Affairs Committee also condemned the government's lack of consultation with victims' groups as part of its plans to deal with the past.
MPs were critical of the UK government's decision that only Troubles killings with "compelling" new evidence and a realistic prospect of prosecution would receive a full police re-investigation.
Following an inquiry into the UK government's dealing with the Troubles, the committee, in its interim report published today, said there was "considerable doubt" about their approach to historical killings.
In March, Northern Ireland Secretary Brandon Lewis said that, after a review, most unsolved cases would be closed and a new law would prevent those investigations from being reopened.
The committee said that decision raises "profound legal, ethical and human rights issues".
The UK government's statement in March marked a significant step away from mechanisms agreed by the UK and Irish governments and main Stormont parties in the 2014 Stormont House Agreement.
The consultation document followed the New Decade, New Approach deal agreed by previous Northern Ireland Secretary Julian Smith and Irish Minister for Foreign Affairs Simon Coveney in January.
The committee said the document's lack of detail on the proposals was "deeply concerning".
Chairman of the committee Simon Hoare MP said the potential permanent closure of legacy cases is "concerning".
"Who will decide which cases should be closed and how? Can these decisions be appealed? What's the definition of 'new compelling evidence' and who will decide that?" he said.
"We'd expected those questions and others to be answered in the usual way in written and/or oral evidence, but the government failed to provide any such evidence. Consequently, this is necessarily an interim report until we receive it.
"We urge the UK government to urgently provide this evidence and invite the Irish government to do the same to help clarify the situation for victims.
"Despite assurances that this policy area would be addressed in a speedy manner, it's seven months since the announcement of the new proposals, and we know nothing more.
"This delay and uncertainty will only perpetuate an unacceptable wait for victims and the families affected that has already gone on far too long."
Committee members said they were "dismayed" by the lack of consultation and engagement with representative groups' on the UK government's new approach before and since its publication.
They described Mr Lewis's statement in March as a "unilateral and emphatic announcement of intent rather than part of a meaningful consultation process".
"Peace building in Northern Ireland has historically been based on establishing consensus and agreement," the report added.
"Merely telling parties or organisations what government either has done or is about to do is not consultation."
Mr Hoare added: "How we tackle the legacy of the Troubles is, understandably, an enormous challenge.
"Doing so effectively requires engagement and consultation with all parties to get them on board. It is imperative that any new system commands cross-community and widespread support for it to have legitimacy.
"The Stormont House Agreement, not without its weaknesses, had appeared to be the basis on which we could move forward, but the government's new proposals are a unilateral departure from that.
"The report found there was a lack of consultation, not even with the very people it is supposed to serve; the victims.
"The move is counterproductive and seems more like a decree than a natural evolution of an agreed framework."
Mr Hoare said that if the UK government fails to include victims' groups and parties, there is "no buy-in, no legitimacy and no credibility for a way forward".
He warned this will delay the wait for truth for families.
The committee has also called for the UK government to clarify its decision to abandon the model of a separate Historical Investigations Unit and Independent Commission for Information Retrieval as set out in the Stormont House draft Bill.
The report said the government's document does not explain how the proposed information recovery mechanism will work and that their "radio silence" since has been "thoroughly unhelpful".
The Northern Ireland Office has been contacted for comment.