Campaigners behind a legal challenge to the government’s controversial Legacy Act have described winning “half” their case.

A judgment at Belfast High Court on Wednesday ruled that the provision for conditional immunity from prosecution for Troubles offences in the Act is not compliant with the European Convention on Human Rights (ECHR).

However, it was also ruled that the Independent Commission for Reconciliation and Information Recovery (ICRIR) – set up in the Act to probe Troubles killings – could carry out human rights-compliant investigations.

Martina Dillon, John McEvoy and Lynda McManus were behind the challenge, questioning the human rights compliance of the Act, and have vowed to fight on, potentially to the Supreme Court.

A large number of supporters accompanied the trio to court on Wednesday, and banners calling for justice for a number of atrocities in Northern Ireland’s troubled past were held aloft.

As they emerged following the delivery of the judgment by Mr Justice Adrian Colton, they were embraced by friends before turning to speak to the cameras.

Ms Dillon, whose husband Seamus was shot dead by loyalist terrorists in Co Tyrone, said the day had not gone exactly as she would have planned, describing winning “half her case”.

“I thought today, I would have won my full case. I got half my case today but I have not given up the fight,” she said.

“I have fought for 26 years and I will continue to fight on,” she said.

“I’ll fight until I get truth and justice.”

Mr McEvoy, who survived a gun attack at a bar in Co Down in 1992, backed her view, adding: “The fight still goes on until we get justice for everybody involved here.”

Ms McManus said while she is grateful her case went forward, she was thinking of the cases of other victims and bereaved whose cases have not gone forward.

Grainne Teggart from Amnesty International described an “important and significant development in a complex case”.

“We welcome the findings from the court today, particularly in respect of immunity from prosecutions and striking that out of the law and also the findings around civil claims, that that immediate ban has also been struck out,” she said.

“That’s an important and significant development for many victims. Today was always going to be round one, we know this is a complex piece of legislation and a complex case so we will continue to fight on until such times as victims’ rights are vindicated.”

Ms Teggart said there are “significant questions” for Secretary of State Chris Heaton-Harris to answer, and urged him to repeal the Act.

“The core part of this legislation was the immunity from prosecution. That has now been stripped out, struck out from the law. So it’s back to Parliament and back to the UK government about what they are going to do next,” she said.

“We urge them to repeal this legislation and put in its place processes that finally prioritise victims and vindicate their rights.”

Solicitor Darragh Mackin, of Phoenix Law, who acts for the families, said: “The reality is this, the Secretary of State’s proposal was built on immunity. Those foundations have been eroded by this court, it’s time to go back to the drawing board.

“We haven’t got everything we wanted today. We’ll fight on.

“The Secretary of State has indicated he will appeal. If so, we’re ready for it, this will go the whole way to the Supreme Court.”