The court has ruled against granting immunity for violence in Northern Ireland's “troubles”.

A new British law giving people immunity from prosecution for crimes committed during Northern Ireland's bloody sectarian conflict, known as the Troubles, would be a violation of human rights, a court in Belfast ruled on Wednesday.

The British government introduced legislation known as the Succession Act, last year, to “promote reconciliation” in the region, despite opposition from all political parties. The law would stop all investigations, civil suits and trials related to the issues that had not been resolved by May 1 and redirect them to independent commission.

It is important to note that the law also includes provisions for conditional amnesty for persons suspected of crimes committed during the Troubles, including serious ones.

The decision at the High Court in Belfast on Wednesday was the result of a judicial review after victims and families affected by the turmoil took the case to court. Judge Adrian Colton, who passed the rulingsaid he believed that granting immunity from prosecution under the act would violate the European Convention on Human Rights.

While the complex ruling is unlikely to affect Britain's ability to enforce some parts of the law from May 1, legal experts say it is a major blow to the country's already fragile Conservative government, whose support has fallen in polls before elections to be held next year.

Problemsdecades of sectarian conflict between Catholic and Protestant communities that gripped Northern Ireland from 1968 to 1998 left an estimated 3,600 people dead in bombings and shootings before a Good Friday peace accord ended the violence.

The conflict still casts a long shadow over Northern Ireland despite decades of peace, with many victims' families still seeking justice and many perpetrators of the violence never brought to justice. But there has long been a fragmented approach to combating unlawful killings, with different legal channels, inquiries and investigations conducted by different agencies.

The new legislation has alarmed human rights groups and has been widely criticized by the public in Northern Ireland, which is part of the UK, and condemned by the government of the neighboring Republic of Ireland.

There were fears the act could derail years of carefully managed peace-building and diplomacy between Britain and Ireland at a particularly difficult time, with Brexit adding to the strain on their relationship.

The law has also spawned several legal battles, including a judicial review. In December, Ireland announced it would challenge Britain at the European Court of Human Rights in Strasbourg, France. The court is a tribunal of the Council of Europe, of which Ireland and Great Britain are members.

The British government is likely to appeal Wednesday's ruling at the Court of Appeal in Northern Ireland and possibly the UK Supreme Court, lawyers involved in other cases related to the legislation said.

Christopher Stanley, a lawyer at KRW Law, one of the firms acting on behalf of relatives of victims of the conflict, welcomed the verdict.

“Politically, this is becoming an increasingly problematic issue for the British government in an election year,” Mr Stanley said. “This is a bad day for the British government. It is a day of some respite for relatives of victims and survivors of violent conflicts.”

But he also said it was “not a victory for families as the UK government will challenge the findings”.

Others seized on the ruling to call on the UK government to review the Inheritance Act.

“This morning's High Court decision confirms what every honest observer knows, that the Government's inheritance laws are incompatible with human rights,” said Claire Hanna, Member of Parliament for Belfast South. “He puts the needs of criminals before the needs of victims and that is not supported by any party in Northern Ireland or on the island of Ireland.”

But the government has promised to push the law forward, said Christopher Heaton-Harris, secretary of state for Northern Ireland. “We remain committed to the implementation of the Heritage Act,” he said.