Mennini is known in Italy as the priest who heard the final confession of the country’s murdered Prime Minister, Aldo Moro, in the 1970s.

The Vatican shielded the priest from ever having to testify in subsequent state hearings concerning Moro’s abduction and murder,[4] until Pope Francis authorized him to do so in 2015.

However, the visit was hailed as a success, largely because the new nuncio established excellent working relations with Orthodox leaders who had originally opposed it.

However, through the nuncio’s fence-mending efforts, the atmosphere gradually began to improve and in December 2009 President Dmitry Medvedev approved the establishment of full diplomatic relations with the Holy See.

[13] As a Nuncio, one of the most important duties which Mennini faced was to facilitate the vetting process for the appointment of a substantial number of new bishops for dioceses in England, Wales and Scotland, referring back the results of confidential consultations to the Holy See.

On 25 February 2013, Pope Benedict XVI accepted the resignation of Cardinal Keith O'Brien, Archbishop of St Andrews and Edinburgh and Britain's then most senior cleric.

A writer in the English Catholic publication The Tablet speculated that Mennini's appointment was recognition that delicate diplomatic work was required for the establishment in Britain of the personal ordinariate for former Anglicans.