Vatican City: Pope Francis has opened the door for women who have had abortions – an act considered a grave sin by the Catholic church – to be absolved if they express contrition and seek forgiveness from their priest.

“The forgiveness of God cannot be denied to one who has repented,” the pontiff wrote in an extraordinary letter that was released by the Vatican on Tuesday.

“I am well aware of the pressure that has led them to this decision. I know that it is an existential and moral ordeal,” he added.

The unprecedented order by Francis, which temporarily allows all priests to grant forgiveness to women who have elected to have an abortion and profoundly regret the procedure, is part of the church’s jubilee year of mercy, which begins on 8 December and runs until 20 November 2016, reported The Guardian.

Within an hour of releasing the letter, the Vatican released another statement in response to a flood of queries, emphasising that the church did not “condone abortion nor minimise its grave effects”.

“The newness [of the order] is clearly Pope Francis’s pastoral approach,” the Vatican said. “Many bishops have granted priests permission to forgive the sin. The fact that this statement is coming from the pope in such a moving, pastoral way, is more evidence of the great pastoral approach and concern of Pope Francis.”

The church added that the fact that the faithful already went to confession to confess their abortions and other “grave sins” was a cause to thank God and to put in practice the mission of the church to “seek out those who were lost”.

Although the letter does not change official church doctrine, it will be seen as further evidence that Francis is approaching his papacy as a liberal-minded reformer and is seeking to reach out to Catholics who believe the church – and its usually uncompromising attitudes towards abortion, homosexuality and divorce – is too harsh and out of touch with modern social views.

It comes as the Vatican is preparing to host a month-long synod on October that will focus on family issues, including whether divorced Catholics ought to be allowed to take communion.

“For Francis, mercy is the key to evangelisation,” said Austen Ivereigh, who has written a biography of the pope. “I think the pope is convinced that the church has lost the priority of mercy in its preaching and he is doing his utmost to restore it.”

He said the move – which he believed was unprecedented – was as if the pope was telling women of the world: “I know you have suffered, come and be released from your guilt.”

Francis has already frustrated some traditional and conservative Catholics – particularly in the US – with his criticism of unfettered capitalism, which he has called “the dung of the devil”, as well as his call for action to combat global warming and phase out the use of fossil fuels. He made waves early on in his papacy when, in response to a question about a Vatican official who was allegedly gay, he responded: “Who am I to judge?”

“Pope Francis’s decision to allow priests to absolve women who have procured abortions consolidates his reputation as the ‘Pope of Mercy’ and as a master strategist in the effort to bring back lapsed Catholics into the fold,” said R Andrew Chesnut, professor of religious studies at Virginia Commonwealth University

Under canon law, women who receive abortions and doctors who perform them – or anyone involved in the procedure – are automatically excommunicated, according to Teresa Berger of the Yale University divinity school.

But, under normal circumstances, those who face excommunication can be absolved if their confessor has received special authority from a bishop to do so – an authority that not all priests have.

While doctors who perform abortions were not explicitly mentioned in the letter, some experts believe that the clemency would also apply to them.

In his letter, Francis said a “widespread and insensitive mentality” had led to the loss of proper personal and social sensitivity.

“The tragedy of abortion is experienced by some with a superficial awareness, as if not realising the extreme harm that such an act entails. Many others, on the other hand, although experiencing this moment as a defeat, believe that they have no other option,” he wrote.

Women who have abortions are not the only people who will receive special clemency as part of the church’s jubilee year. In his letter, the pope also granted special forgiveness to followers of the Society of St Pius X, known as Lefebvrists, a breakaway conservative order describing itself as a “resistance movement” against the Vatican.

Francis said he had heard from several bishops of some followers’ “good faith and sacramental practice” and that, “motivated by the need to respond to the good of these faithful”, those who approached priests of the rebel authority to receive forgiveness shall be absolved of sins. While those priests are considered ordained, they are not usually considered authorised to minister.

John Allen, a Vatican expert, wrote on the Crux news website that the news represented a “daring double-play”.

“Putting these two olive branches into the same package could be seen as another effort by Francis at political equilibrium, reminiscent of his decision in April 2014 to beatify the late popes John XXIII and John Paul II, together, icons for the Catholic left and right respectively,” Allen wrote.

While the concession would be welcomed by many Catholic liberals who have urged the church to be more compassionate, conservatives would likely cheer the approach to the Society of St Pius X.

Pope Francis already announced earlier this year that he planned to appoint some priests with the power to forgive abortion as part of the year of mercy, but his letter on Tuesday made it clear that his approach would reach far more people than originally forecast.