Westminster MPs have been accused of putting "personal agendas ahead of the people" by voting overwhelmingly in favour of amendments to liberalise abortion and gay marriage laws in Northern Ireland in the event that devolution is not restored.
Peter Lynas, director of the Evangelical Alliance Northern Ireland, said it was a "deeply sad day" for Northern Ireland after the vote in the House of Commons on Tuesday night.
The Commons voted 383 to 73 to extend same-sex marriage to the region, and 332 to 99 to give it the same abortion access as the rest of the UK.
The votes were held as Stormont remains suspended, as it has been since January 2017 due to political deadlock.
The changes voted on tonight in Westminster will only come into effect if devolution is not restored by 21 October.
Mr Lynas said that the votes "fundamentally undermine devolution" and that Westminster MPs had "no mandate" to change the law in Northern Ireland.
"This is a deeply sad day as MPs vote to remove legal protection from the most vulnerable members of society. I understand some will see this as a victory for equality and choice," he said.
"But equality must treat both mother and child fairly and choice must recognise both lives in a pregnancy.
"Unfortunately Westminster MPs have placed personal agendas ahead of the people and the peace process in Northern Ireland.
"For over 50 years Northern Ireland has chosen a different way which means 100,000 people are alive here who otherwise would not be. Today that changes."
He added: "On marriage, it is a covenant commitment between a man and a woman. Many will see this as a victory for equality. However, confusing equality with the redefinition of marriage is a mistake.
"It is sad that MPs with no mandate have chosen to ignore devolution and change the law in NI."
A bid to ease abortion laws in Northern Ireland was voted down as recently as 2016.
The changes to Northern Ireland's current abortion laws would effectively remove safeguards on terminations up to 28 weeks.
Christian advocacy group CARE was critical that the amendments were passed by MPs who do not represent any Northern Ireland constituencies, and without any consultation with the people of Northern Ireland.
This is despite recent polling by ComRes finding that 64 per cent of people in Northern Ireland, including 66 per cent of women, did not think Westminster should interfere with the country's abortion laws.
CARE Chief Executive, Nola Leach said: "Today, most MPs who were in the Commons have chosen to bypass devolution in Northern Ireland and impose a radical new abortion regime on the Province, without any consultation with people who live there.
"This is a tragic outcome and one we believe will have devastating consequences for women and babies across Northern Ireland.
"Westminster MPs who do not represent NI constituencies have shamelessly forced abortion law change on the people of NI.
"The consequences of this vote will be felt all over the United Kingdom and it will likely lead to a further liberalisation of the law on abortion—a law that has already resulted in 9 million babies being aborted since 1967.
"The amendment MPs have backed today was based on a report by an unelected UN sub-committee whose recommendations were non-judicial and non-binding.
"Today is a backwards step when it comes to the rights of women and babies. It is not a triumph of human rights, but a subverting of true democracy."
A spokesperson for Right To Life UK, Clare McCarthy said that the abortion amendment was an "unconstitutional and disrespectful attempt to override devolution in Northern Ireland and to attempt to impose abortion on demand on the Northern Irish people".
"The law on this issue should be a decision for the people of Northern Ireland and their elected representatives, not for MPs in Westminster to decide," she said.
"It is totally constitutionally inappropriate to bring forward abortion amendments to a Bill which has nothing to do with abortion in any way, to legislate on such a sensitive matter. Any imposition of abortion law on Northern Ireland from Westminster would undermine devolution and the Good Friday Agreement.
"No consultation on this amendment was possible. The people of Northern Ireland had next to no opportunity to voice their opinions.
"Westminster must respect the principle and spirit of devolution and ensure the people of Northern Ireland, through their elected representatives, get to decide on what law and policy should apply in that jurisdiction."