Sir Declan Morgan's claim the north's political parties are responsible for a failure to implement the Stormont House Agreement has been challenged by a victims' group.
Relatives for Justice CEO Mark Thompson said the British government was "responsible for the non-implementation" of the legacy mechanisms agreed in 2014.
In an interview with The Irish News, Sir Declan said the best way for politicians opposed to the British government's controversial legacy legislation to thwart it was "by implementing the Stormont House Agreement".
"They've had nine years and it hasn't been implemented," he said.
The former lord chief justice has faced criticism and calls to resign as chair of the newly-established Independent Commission for Reconciliation and Information Recovery (ICRIR).
Mr Thompson disagreed and said Sir Declan was seeking to "displace responsibility" onto the Stormont parties.
"It could be argued that Declan Morgan is rewarding bad behaviour by the UK government in facilitating attempts to unilaterally abandon Stormont House Agreement and in accepting the role of chief commissioner for the ICRIR, which contains what amounts to a blanket amnesty," he said.
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The Relatives for Justice spokesman also questioned Sir Declan's assertion that the forthcoming Northern Ireland Troubles (Legacy & Reconciliation) Bill, which faces almost universal political opposition across Ireland, could meet the retired judge's three "core values".
The Derry-born KC said the commission could "deliver for everybody", while also being compliant with the European Convention on Human Rights (ECHR) and "in the spirit of the Good Friday Agreement".
Mr Thompson said the aspiration that the ICRIR deliver for everybody was "a very subjective exercise outside of the rule of law".
"His second test is that the ICRIR must be consistent with the spirit of the Good Friday Agreement - this bill breaches the Good Friday Agreement," he said.
"Further, since the signing of the Good Friday Agreement progress on all the difficult issues has only ever been achieved when both governments work closely together along with all the parties."
The Relatives for Justice chief described the legislation as a "unilateral departure from the Good Friday Agreement".
"The third core value test outlined by Declan Morgan was that the ICRIR must be compliant with the ECHR - every single human rights expert, and international body, has clearly indicated that should this legislation become law then it will be in violation of the ECHR," he said.
