The House of Lords in the UK Parliament rejected an amendment calling Islamic State's atrocities against Christians and minorities a "genocide" in the Middle East by 148-111 votes.
If the upper house had passed the amendment, it would have moved on to the High Court judge for final approval.
The decision to call it genocide would have had huge ramifications, according to reports, including being required to give immediate asylum to refugees from Syria and Iraq.
Those who supported the amendment were upset after it failed to pass through the house. Lord David Alton had urged the government to call ISIS persecution a "genocide," following US Secretary of State John Kerry's statements on March 17.
"This was a day when Britain neither salved its conscience or offered practical help but chose to look the other way. When historians come to consider the lamentable failure of both parliament and government to speak and act they will surely conclude that we failed to recognize the crime above all crimes," Alton said in a statement after the amendment was taken down.
"This should not have been a day for party whips and scaremongering arguments - such as being flooded with genocide victims - none of which brings Parliament credit," he said.
Those who opposed the amendment said that the resolution to call minority persecution a genocide lies with international judicial bodies such as the UN.
Recently, Kerry had said: "In my judgment, Daesh [the Arabic acronym for the Islamic State] is responsible for genocide against groups in areas under its control, including Yazidis, Christians and Shiite Muslims. Daesh is genocidal by self-proclamation, by ideology, and by actions."
Last month, the European Parliament called the actions of ISIS as genocidal, and asked the UN and International Criminal Court to bring ISIS to trial for crimes against humanity.
"So-called 'ISIS/Daesh' is committing genocide against Christians and Yazidis, and other religious and ethnic minorities, who do not agree with the so-called ISIS/Daesh interpretation of Islam," the EU said Keen. He added that such passing such an amendment would be a "potential disaster" for immigration policy in Britain.
