Italian President Giorgio Napolitano has refused to sign an emergency decree to stop the assisted death of a woman who has been in a coma for the past 17 years.
Eluana Englaro, 37, has been in a coma since January 1992 following a traffic accident.
An official statement from Mr Napolitano's office said the decree passed earlier by Prime Minister Silvio Berlusconi's cabinet was unconstitutional.
Mr Berlusconi had said that in the case of Mr Napolitano's refusal he would immediately convene parliament to approve the edict, which would oblige the president to sign.
'Until we have a law about end-of-life issues, nutrition and hydration cannot be suspended under any circumstances by those who are care-givers of people who are not self-sufficient,' Mr Berlusconi said.
Ms Englaro's case has gripped Italians and triggered a debate over euthanasia, which is vigorously opposed by the Catholic Church.
Her father won the right to stop feeding her intravenously as the result of a 13 November court order.
Doctors at a hospital in the northeastern Italian town of Udine have already started reducing her nutrition.
A priest celebrated mass for anti-euthanasia activists outside the hospice today and a small group of protesters put up banners reading 'Berlusconi, save Eluana'.
