Pope Francis is today meeting victims of sexual abuse by clergy for the first time since his election to papacy.

Six victims, two each from Britain, Ireland and Germany, were to attend a private Mass in the Vatican this morning, before receiving an audience with the pontiff.

Francis has been vocal in his condemnation of sexual abuse in recent months, following years of allegations levelled at the Catholic Church regarding the behaviour of priests and other clergy.

In May he denounced sex abuse as "an ugly crime...because a priest who does this betrays the body of the Lord".

He also compared abuse to devil worship, describing it as like "a satanic Mass" and adding that "we must go ahead with zero tolerance".

Despite this, however, the Pope has been subject to much criticism for his failure to act quickly on the matter, and David Greenwood, Chairman of Stop Church Child Abuse, told Christian Today that today's offering is insufficient.

"I cannot understand why any survivor of clergy sex abuse would want to meet the Pope. My view is that the Pope should be visiting them in their own homes and begging their forgiveness," he said in May.

"Successive Popes have made and promoted rules for Bishops and priests which have shielded clergy from investigation by the police throughout the world. The church's lamentable behaviour has been criticised by survivors, lawyers and now two United Nations committees (the committee for the rights of the child and the committee against torture) yet Pope Francis and other senior clerics continue to defend the church."

He finished: "The Pope now has an opportunity to put his organisation's house in order by acknowledging the UN's criticisms and implementing their recommendations but sadly I very much doubt he or his officials are serious about promoting child protection".

Anne Doyle of Bishops Accountability, a US-based group dealing with abuse in the Catholic Church, was more positive about today's meeting. 

She told Reuters news agency: "I think it's very important that the pope meet with victims."

"We know that this pope is capable of compassion and his refusal to meet with sexual abuse victims so far has been inconsistent with the mercy he has shown with so many marginalised. This is something that he had to rectify."

Since his election Francis has set up a committee which focuses solely on clergy abuse – a move that has been welcomed by many campaigners.

"The Church is aware of this damage, it is personal, moral damage carried out by men of the Church, and we will not take one step backward with regards to how we will deal with this problem, and the sanctions that must be imposed," he promised in April.

"On the contrary, we have to be even stronger."