Pope Francis has declared that all priests can "absolve" women who have had an abortion if they confess and repent during the coming Year of Jubilee.

Pope Francis has issued a decree to all Catholic priests that during the coming holy year, which begins in December, any woman who seeks absolution with a "contrite heart" for having had an abortion can be forgiven.

The Catholic Church in its doctrine regards abortion as a moral evil tantamount to murder, and under canon law anyone who has an abortion is automatically excommunicated. The excommunication can only be lifted if the woman approaches a bishop in order to confess the abortion. He can then grant absolution himself or authorise a priest to absolve her.

The Pope's move in the coming Jubilee Year of Mercy, to start on 8 December and end on 20 November 2016, marking the 50th anniversary of the end of the Second Vatican Council in 1965, will for the first time allow all priests to absolve a woman for an abortion without the need to involve a bishop.

Pope Francis set out his plans for the Jubilee in remarks published today by the Vatican.

He laments the changes in society in attitudes towards "life" issues, which cover assisted dying and contraception as well as abortion.

"A widespread and insensitive mentality has led to the loss of the proper personal and social sensitivity to welcome new life," he writes.

"The tragedy of abortion is experienced by some with a superficial awareness, as if not realising the extreme harm that such an act entails."

He acknowledges that many, while experiencing it as a defeat, believe they have no other option.

"I think in particular of all the women who have resorted to abortion. I am well aware of the pressure that has led them to this decision. I know that it is an existential and moral ordeal.

"I have met so many women who bear in their heart the scar of this agonising and painful decision. What has happened is profoundly unjust. Yet only understanding the truth of it can enable one not to lose hope."

The Pope says the forgiveness of God cannot be denied to one who has repented, especially when that person approaches the sacrament of confession "with a sincere heart".

"For this reason too, I have decided, notwithstanding anything to the contrary, to concede to all priests for the Jubilee Year the discretion to absolve of the sin of abortion those who have procured it and who, with contrite heart, seek forgiveness for it."

He urged priests to be genuinely welcoming to the penitents, while not shying away from the "gravity of the sin".

The liberal Catholic organisation Catholics for Choice gave a guarded welcome.

"Pope Francis, unlike his two predecessors, Pope John Paul II and Pope Benedict XVI, is trying to bridge the gulf between what the hierarchy says and what ordinary Catholics really do in their lives," they said.

Jon O'Brien, president of Catholics for Choice, added: "It's abundantly clear and the statistics are stark: What Catholics practice is different than the dictates of the bishops. Ninety-nine percent of US Catholic women have used a method of birth control the bishops don't like, and we know that Catholic women have abortions at the same rate as those of other faiths and no faiths."

But he said he did not believe Catholic women would be queuing up for forgiveness, as they had long ago decided to go their own way on issues of reproduction and contraception. "Catholic women know that they can in good conscience disagree with the hierarchy and still be good Catholics in good faith. The very narrowness of Francis' statement on having a particular year of forgiveness suggests that he still has a blind spot when it comes to women and what they want."

O'Brien described it as a "warning shot fired across the bow" to bishops who have waged culture wars over the bodies and lives of women. "This is a pope who is not stuck in the pelvic zone, and perhaps his message on how he thinks about abortion is more for his brother bishops than Catholics in the pew."

However, the Pope's comments are likely to alarm traditionalists. The conservative Catholic commentator Chris Gillibrand said this was an indication of his agenda for the forthcoming Synod on the Family in Rome: "The Pope is showing now liberality on abortion and traditional Catholicism to further his progressive agenda at the October synod."

Normally, jubilees are held every 50 or 25 years, making this one an "extraordinary" holy year. The last one was Pope John Paul II's Great Jubilee of 2000. The tradition, which originates from the Hebrew bible, was begun in the Catholic church by Pope Boniface VIII in 1300.