Amnesty International has rejected a Vatican appeal for Catholics to withdraw support for the group over its call to decriminalise abortion.
Amnesty's new position seeks to give women access to abortion when their health or human rights are in danger.
"The Catholic Church, through a misrepresented account of our position on selective aspects of abortion, is placing in peril work on human rights," Kate Gilmore, Amnesty's deputy secretary-general, said.
She was responding to comments by Cardinal Renato Martino, the Vatican's justice minister, who accused Amnesty of "betraying its mission" and said "individuals and Catholic organisations must withdraw their support" from the group.
Ms Gilmore said Amnesty was not promoting abortion as a universal right but stressing that women have a right to choose abortion when their human rights have been violated, particularly in cases of rape and incest.
"We are saying broadly that to criminalise women's management of their sexual reproductive rights is the wrong answer," she said.
"We live alongside people's life experiences. We don't run a theocracy. We have to deal with the rape survivor in Darfur who, because she is left with a pregnancy as a result of the enemy, is further ostracised by her community," Ms Gilmore said.
Cardinal Martino said that by taking its new stand on abortion, Amnesty had "disqualified itself as a defender of human rights".
"To selectively justify abortion, even in the cases of rape, is to define the innocent child within the womb as an enemy, a 'thing' that must be destroyed," Cardinal Martino said.