The head of the Catholic Church in Ireland has vowed to mount a strong campaign against any referendum on the eighth amendment.

Archbishop Eamon Martin says Pope Francis will use his visit to Ireland in 2018 to speak out against abortion.

In an interview with the Sunday Business Post, Archbishop Martin said abortion was a core issue for the Catholic church.

The Citizens' Assembly will report next year on whether the repeal of the eighth amendment should be put to a referendum.

The Archbishop said that if the issue is put to a vote, the Catholic church will run a much stronger campaign than it did during the marriage equality referendum.