Voters go to the polls May 25 in a referendum on whether to remove the Eighth Amendment, which was passed in 1983 and gives unborn children an equal right to life "with due regard" to the life of the mother. Minister for Health Simon Harris has announced plans to allow abortion on demand up to 12 weeks, up to 24 weeks on unspecified grounds for the health of the mother, and up to birth where the child is diagnosed with a life-limiting condition that means he or she may not live long after birth.

In a message read at Masses across the Archdiocese of Armagh, Northern Ireland -- which includes parts of the Irish Republic -- Archbishop Eamon Martin urged worshippers to be "missionaries for the cause of life."

The archbishop, president of the Irish bishops' conference, pointed out that Ireland's Supreme Court has clarified that "if the Eighth Amendment is repealed, unborn children in Ireland will have absolutely no constitutional rights."

"A vote to repeal the Eighth Amendment on May 25 would therefore pave the way for a very liberal abortion regime in Ireland, including completely unrestricted access to abortion during the first three months of pregnancy," Archbishop Martin said.

He warned that this was a departure from the current medical and legal culture in Ireland, "where the equality of life of a mother and her unborn baby is written into our constitution."

"Women's lives are precious, to be loved, valued and protected. Their babies' lives are precious, to be loved, valued and protected. Both lives deserve protection from the tragedy and irreversible decision of abortion," Archbishop Martin said.

He insisted that "to be against abortion is not simply 'a Catholic thing.' The innate dignity of every human life is a value for the whole of society -- for people of all faiths and none. It is rooted in reason as well as in faith. To take away an innocent human life can never be simply a matter of personal choice."

The archbishop concluded his message with a direct appeal to voters: "When you go inside the voting booth on May 25, pause and think of two lives -- the life of the mother and the life of her baby -- two hearts beating; two lives which are both precious and deserving of compassion and protection.

"Love them both. Pray for both. Choose life for them both. Say 'no' to repealing the Eighth Amendment, and then do everything you can to ensure that our country will always provide the best possible care and support for all mothers and their unborn children," he writes.

In Dublin, Archbishop Diarmuid Martin had asked parishes to hold a special time of prayer for the protection of life. Many parishes held holy hours, and a message from the archbishop was read at Masses.

He told Massgoers that the church "must always be pro-life. That means that the Christian community must be a beacon of support for life, especially at its most vulnerable moments, and a beacon of support at vulnerable moments of any woman or man along their path of life.

"Christians must be pro-life when it comes to the unborn and those who are vulnerable at the end of their lives," Archbishop Martin wrote.

Reflecting on the past, Archbishop Martin said that "for too long, a mentality was common in Ireland in which single mothers were ostracized and humiliated. This narrow moralistic culture was often sadly enhanced by the attitude of the church."

He said "it was women who stood up and challenged that culture and affirmed their desire and right to be able to keep and give love to their children. We owe a debt to those women who, then and now, witness to life.

"Ireland has a great record in the care of mothers and of children. The overall ethos of medicine in Ireland has been marked by a passionate commitment to do all to protect the life of both mother and child," Archbishop Martin wrote.

He warned that "repealing the Eighth Amendment is not about permitting limited abortion. It would bring about a radical change to our broad pro-life culture. It would end any constitutional protection whatsoever for the unborn. Proposed future legislation would permit abortion without restriction up to 12 weeks, but also permit abortion on physical and mental health grounds up to six months."

The archbishop said a decision to remove the right to life of the unborn from the constitution would be "a point of no return."

"It seems incongruous that, just as medical science allows us to understand much more about the evolution of the baby in the womb and his or her originality and unique identity, that we should simply throw out all constitutional protection of the unborn child.

"For that reason, I will be voting 'no'," the archbishop wrote.

Voting runs May 25 from 7 a.m. to 10 p.m. A result is expected May 26.