Northern Ireland's Human Rights Commission has accused the Assembly of neglecting women's rights after it rejected proposals to relax abortion laws.
However Christian campaigners said the existing rules provide vital protection for women, after Stormont members voted by a majority of 59 to 40 against amending legislation to allow terminations in cases of fatal foetal abnormality and sexual crime.
Unlike other parts of the UK, the 1967 Abortion Act does not extend to Northern Ireland, where abortions are banned except where the life or mental health of the mother is in danger.
Anyone who performs an illegal termination could be jailed for life. The law has been the subject of a bitter legal battle and landmark ruling.
Hundreds of women travel to other parts of the UK for abortions every year.
Chief human rights commissioner Les Allamby said: "The Northern Ireland Assembly has failed to act in accordance with the court judgment.
"Our elected representatives have neglected the fundamental rights of vulnerable women and girls facing the most difficult circumstances, when they could have resolved the situation."
In cases of fatal foetal abnormality, Belfast High Court judge Mr Justice Mark Horner concluded the mother's inability to access an abortion was a "gross interference with her personal autonomy" while a disproportionate burden was placed on victims when a sexual crime occurred.
A proposal to legalise the termination of pregnancies where the foetus cannot survive outside the womb was tabled by Alliance Party MLAs Stewart Dickson and Trevor Lunn.
Callum Webster of the Christian Institute lobby group said: "It is heartening that the majority of MLAs have voted to uphold the sanctity of life today at Stormont.
"T here has been a media campaign to undermine the legal protections afforded to our unborn children, but thankfully politicians have resisted that co-ordinated pressure."
Justice Minister David Ford brought forward the proposed change and said the matter could remain in limbo for some time.
Abortion has long divided opinion in Northern Ireland.
In 2013 young mother Sarah Ewart went public about having to travel for an abortion after being told her baby had no skull and could not survive after birth.
Last year Mr Justice Horner ruled that the failure to provide legal exceptions to the prohibition breached human rights obligations.
His declaration of incompatibility did not immediately lift the ban but placed an onus on the Assembly to legislate.
A date for a legal appeal against the ruling is to be set on Friday.
Stormont's chief legal adviser, attorney general John Larkin QC, is among those opposed to changing the law and has outlined concerns that the move could breach obligations under the UN Convention on the Rights of Persons with Disabilities (UNCRPD).
Mr Lunn accused opponents of lacking compassion and choked back tears as he recalled having to make the "painful" decision to access a termination because of a fatal foetal abnormality many years ago.
His baby died while arrangements were being made, the Assembly was told.
"The pain of that decision lives with us today," said Mr Lunn.
Ahead of Wednesday night's debate the DUP said it wanted the Health Minister to convene a commission to examine the issue of abortion and report back in six months.