The meeting was requested following an invitation made to the pope by the Irish Catholic Bishops' Conference to visit Ireland for the World Meeting of Families in two years' time.

It is understood that Mr Kenny was meeting with Pope Francis to address the issue of the six outspoken Irish priests who have been silenced by the Catholic Church.

A reliable clerical source told RTÉ News that the Taoiseach spoke to at least one of the priests concerned before departing for Rome.

Under the pontificates of St Pope John Paul II and Benedict XVI, the writings of the six Irish priests were ordered to be censored by local church authorities.

One of them, world-renowned theologian Fr Seán Fagan, died last July.

Another, Fr Tony Flannery, has been removed from ministry because he refused to recant in writing his statements disagreeing with the church's absolute ban on ordaining women priests, with its ban on artificial contraception and with its teaching on homosexuality.

The other four must submit anything they propose to publish to church censors.

They are: journalist and broadcaster Brian D'Arcy (who spoke about the church in an in-depth interview with Hot Press in September), theologian Fr Owen O'Sullivan, former editor of Reality magazine Fr Gerry Moloney and church historian Fr Iggy O'Donovan.

Mr. Kenny's visit follows his attack on the Catholic Church's response to clerical child abuse back in 2011. His denunciation of the Vatican's attitude to the abuse led to the closure of the Irish embassy to the Holy See, a low point in Irish-Vatican relations.

Since then, however, relations have thawed and the Government has reopened its embassy in Ireland.

Mr Kenny was expected to tell the pontiff that the State would extend every courtesy to facilitate his visit.

The question of whether he would visit Northern Ireland was also likely to come up.

The two men were also expected to discuss the recent developments within the European Union, including the migration crisis, an issue which Pope Francis has often spoken strongly about.

Meanwhile, Irish activists have been vocal about the Pope's visit, questioning the timing of the visit in relation to the declining influence of the Catholic Church in Ireland, as well as in relation to the Repeal the 8th movement.

We need to hold an alternative to the Popes Visit in Aug '18. Big numbers. Maybe a big gig at the Papal Cross. #repealthe8th #secularschools

— ⓧℙⅈⓡ (@xPIr) November 28, 2016

Great news! We cannot wait to welcome Pope Francis #papalvisit #ireland https://t.co/t4qimkw311

— REinColaisteMuire (@ReColaisteMCobh) November 28, 2016

Plenty of time for to get a line of 'No Pope Here' knickers designed & launched. #papalvisit

— Jan Ní Shuilleabháin (@Sharrow_ie) November 28, 2016

The fact that Enda Kenny sees a potential papal visit as landmark for retirement suggests he's more out of touch than I gave him credit for

— Danielle Barron (@MedEdHead) November 25, 2016