Chief Rabbi Ephraim Mirvis has condemned a Bill which would allow doctors to end the lives of terminally ill patients.
The Assisted Dying Bill, which was due to be debated in the House of Lords today, would permit lethal drugs to be administered to people with less than six months to live.
Rabbi Mirvis said: "In the light of Jewish tradition, this Bill seems to me to be irresponsible and dangerous. Life is a gift from God and it is not ours to cut short.
"The focus of this initiative is profoundly misguided. Instead of promoting assisted dying we should be concentrating our attentions on assisted living."
Rabbi Mirvis is one of 23 faith leaders who have signed an open letter against the Bill. Other signatories include Archbishop of Canterbury Justin Welby and Cardinal Vincent Nichols, the Catholic leader in England and Wales.
Life is a gift from God and not ours to cut short
They described the prospective legislation as a "grave error - this is not the way forward for a compassionate and caring society".
However, Rabbi Laura Janner-Klausner, the senior rabbi for Reform Judaism, declined to sign the letter. She said: "If I put my view to this, it might take away from our rabbis who have diverse views on the issue. We are not going to take a whip on this."
The latest research shows that the majority of Jews, Anglicans and Catholics support assisted dying, whereas Muslims, Baptists and Hindus are against it.
Professor Linda Woodhead, a sociologist at Lancaster University, commissioned a poll of 4,500 people last July, which showed that 70 per cent of the 162 Jews in the sample said they were in favour of assisted dying.
Prof Woodhead said she believed the figure would have increased over the past 12 months.
"The number of people of faith who support assisted dying has certainly got higher since then. Religious leaders seem to be out of touch," she said.
But Reform rabbi Jonathan Romain, the founder of the Inter-Faith Leaders for Dignity in Dying group, said he was supporting the Bill.
In this week's JC, he writes: "This is difficult territory, but it is religiously appropriate to try to navigate it. If there is a right to die well - or at least to die as well as possible - it means having the option of assisted dying, whether or not it is taken up."