The Pope has told a Vatican commission to work on a new process for excommunicating Catholics convicted of corruption or mafia-related crimes.

The move follows his condemnation of corruption in a foreword to a book by Cardinal Peter Turkson, in which Francis described it as 'a form of blasphemy, this cancer that weighs on our lives'.

More than 50 lawyers, bishops, UN representatives and victims of organised crime met at the Vatican last week for an 'International Debate on Corruption'.

Turkson himself said of the gathering: 'We conceived of this meeting to face a phenomenon that leads to the trampling of the dignity of people.

'Therefore it is up to us, and this Dicastery, to be able to protect and promote respect for the dignity of the person. And for this reason we seek to attract attention to this matter.'

Archbishop Silvano Tomasi said: 'Our effort is to create a mentality, a culture of justice, that fights corruption and promotes the common good.'

The move against the mafia marks a step change in Vatican policy, in which involvement in organised crime becomes literally unpardonable because it is a way of life rather than a single sin.

Excommunicated Catholics cannot take communion or be married in church.

Organised crime is entrenched in Italy and in several South American countries including Pope Francis' home of Argentina. Francis has been severely critical of the closeness of the Church to mafia figures, which sees children named after mobster godfathers and religious processions stopping outside the homes of mob bosses as a form of respect.