The sister of one of jailed loyalist killer Michael Stone's victims is mounting a new legal bid to ensure he remains behind bars.
In September last year the High Court ruled that Sentence Review Commissioners (SRC) could consider the Milltown Cemetery bomber's application to be freed early for a second time.
Although 64-year-old Stone was turned down at that stage, there is nothing to stop him making further requests in future.
Lawyers representing Deborah McGuinness have now taken their legal battle to the Court of Appeal.
Lord Chief Justice Sir Declan Morgan listed the case for a one-day hearing in May.
Ms McGuinness's brother, Thomas McErlean, was among three mourners Stone killed in the attack on an IRA funeral at Milltown graveyard, west Belfast in March 1988.
The former UDA man was also the gunman in three other killings.
Stone is currently serving a 30-year term for his sectarian murder campaign.
He had been freed early as part of the Good Friday Agreement arrangements in 2000.
Six years later, however, he was sent back to jail after trying to enter Parliament Buildings at Stormont, armed with explosives, knives and an axe, in an attempt to murder Sinn Fein leaders Gerry Adams and Martin McGuinness.
Stone denied it had been a bid to kill the politicians, instead claiming it was an act of performance art.
As it stands he must remain in jail in 2024.
His application to the SRC for release again under the terms of the Good Friday Agreement led to last year's court battle.
Stone's legal team contended that the legislation does not limit the number of times a prisoner can seek to be let out.
A High Court judge ruled the body has legal power to consider further applications after identifying no prohibition in the Northern Ireland (Sentences) Act 1998.
Even though Commissioners then assessed and denied Stone's request, Ms McGuinness's lawyers are challenging a judicial determination they believe leaves him free to try again at any point.
According to their case he is not entitlement to any second chance after being returned to prison for the Stormont attack.