A British government challenge to a court ruling that part of its controversial Legacy Act is unlawful is to begin on Tuesday.
In February the High Court in Belfast ruled that parts of the legislation are unlawful, including offering conditional immunity from prosecution for Troubles-era offences and shutting down civil actions.
The contentious Northern Ireland Troubles (Legacy and Reconciliation) Act passed into law last September.
From May 1 all civil cases and inquests that were not at their findings stage were halted as part of the contentious act.
In the weeks before the cut-off date came into force, several high-profile inquests linked to allegations of collusion were abandoned by coroners amid concerns over a failure by state bodies to disclose key information.
Responsibility for investigating all legacy cases has since been transferred to the Independent Commission for Reconciliation and Information Recovery (ICRIR).
Many victims, and relatives of those who died during the Troubles, are strongly opposed to the ICRIR and believe it is designed to protect state participants from accountability.
As part of this week’s legal action a cross-appeal will also be heard over a separate ruling that the ICRIR has sufficient independence and powers to effectively investigate Troubles-related deaths and offences.
The Legacy Act has faced widespread cross-community opposition, resulting in some relatives and victims launching legal action earlier this year.
The Irish government has also voiced its concerns and launched a separate inter state case at the European Court of Human Rights.
Labour MP Hilary Benn, who is expected to be the north’s next Secretary of State, has said he will “repeal and replace” the act if his party wins the forthcoming Westminster election.
Martina Dillon, whose husband Seamus was shot dead by the LVF near Dungannon, Co Tyrone, in December 1997, is one of several relatives and victims who will be represented by Phoneix Law during this week’s legal proceedings.
Ms Dillon said she wants to know the circumstances of her husband’s death.
“I want an inquest and that’s what I’m fighting for,” she said.
“It’s not only me, there’s hundreds of individuals.
“The only thing I ever asked for…was for that inquest, for truth and justice and that’s all I ever wanted.”
Ms Dillon said she is determined to keep going
“I don’t care how long it takes me, as long as I have breath in my body, I will fight the whole way.”
A spokesman for the Northern Ireland Office said it does “not comment on ongoing cases”.