Invoking the example of the late John Paul II, four Italian nuns have asked for Church permission to make "living wills" to ensure that if for any reason they fall into a "vegetative" coma they are not kept alive artificially.

The move contradicts the Vatican and Catholic Church response to the case of Eluana Englaro, an Italian woman who has been in a comatose "vegetative state" for nearly 17 years. Last week there were Vatican and Church protests when the Court of Cassation, Italy's top appeals court, ruled that Ms Englaro could be allowed to die through the removal of feeding tubes.

Ms Englaro has been in a coma since a 1992 car accident in the northern Italian city of Lecco, in Lombardy. Before the accident she had said that if anything ever happened to her and she was left in a coma, she wanted to be allowed to die.

Sister Ildefonsa, 74, who has been a nun since the age of 17 and has cared for patients at a Genoa hospital for the past 25 years, said she and three other nuns had also "verbally asked our superiors to allow us to make biological testaments". She said she was "waiting for a response. I can be patient, the Church needs time to decide certain things".

Sister Ildefonsa, known to all as Sister Ilde, said she was loyal to Church teaching. "But I do not want to be reduced to a vegetable. If that is my fate I want to be allowed to go in peace." She said she had read that John Paul II had asked "Let me go to the Father" when he was near death three years ago. The dying pontiff refused to return to hospital for further medical treatment, preferring to spend his last days in the Vatican.

Sister Ildefonsa, who did not refer directly to the Eluana Englaro case, said she had made up her mind after one of the nuns in her order had had a stroke and was "attached to tubes and machines" for nearly three months before dying. "I thought to myself, I don't want to be attached to machines, I don't want to end like that. Why prolong the suffering, both for oneself and for others?"

The nun said she had accompanied many patients on their "last journey". "My only brother died recently. We said the rosary together many times, he was suffering, and he said to me, 'I'm tired , it's enough." I prayed for the Lord to open his arms and receive him."

Sister Ildefonsa said some people claimed that "the last days of suffering bring you closer to God, but I am not sure whether they bring you salvation or damnation. Science and medicine can make mistakes. It is better to let Providence take its course".

She said she believed firmly in the sanctity of life "from conception onward" . She had cared for severely mentally impaired children, "and when visitors say, what is the use of such a life, I reply, it is of use to you, because you can ask yourself what you can do for them".

Formerly Elsa Busatta, from a village near Padua, Sister Ildefonsa told Il Secolo XIX, the Genoa paper, that she had become a novice even though she was engaged at the time. Her fiance, who had accepted her vocation, later died in an accident. "I always visit his grave when I go back".

Her stand is in contrast to that of the nuns who look after Ms Englaro at Lecco. In a letter to L'Avvenire, the Italian Catholic daily, the nuns at Lecco said "Our hope, and that of many like us, is that the death by hunger and thirst of Eluana, and others in her condition, will not be carried out. If there are those who consider her dead, let Eluana remain with us, who feel she is alive".

Eugenia Roccella, the Italian deputy minister of Welfare, said it as "absurd" to assume that comas were "irreversible". Although rare, there were documented cases of people "in a vegetative state" who recovered sufficiently to make "partial contact with the external world" even after long periods of time, Ms Roccella said.

However Carlo Alberto Defanti, Ms Englaro's doctor and a neurologist, said the chance of such a recovery were "0.0001 percent" and therefore "practically non-existent". He said that if Ms Englaro were deprived of water and nutrition she would not suffer "any more than a patient under total anaesthetic would suffer".