Irish bishops have spoken out in defence of unborn children after the Irish government launched its campaign in favour of repealing the country's restrictive abortion laws.

Prime Minister Leo Varadkar launched the 'Yes for Repeal' campaign which is widely supported in the government and media on Saturday, saying, 'We should be a country in which we trust women and trust doctors to decide on what's right.'

After a referendum in 1983 an amendment was inserted into the Irish constitution banning abortion in almost all circumstances. Many women travel from Ireland to the UK for abortions and repeal campaigners say the case of Savita Halappanavar, who died in Galway hospital after her request for a termination was denied, highlights the failings of the current system.

However, according to Crux, Bishop Denis Brennan of the Diocese of Ferns said the move 'will strip the voiceless of their most fundamental right and make all talk of any other human rights irrelevant for them'.

He said in a pastoral message on Sunday that voters would be the unborn baby's last line of defence and that they should act in the best interests of the child.

Archbishop Eamon Martin of Armagh, the Primate of All Ireland, told Crux on April 17: 'Abortion is not wrong because the Catholic Church says it's wrong, abortion is wrong in itself. The taking of a life of an innocent human being at any stage in its development is gravely wrong and can never be justified, and that's not just because I said it.' He said bishops were encouraging the lay faithful 'to be gently acting as missionaries for life'.

Irish bishops have stressed the issue is not one of religious rights but of human rights.

The referendum will take place on May 25 during the run-up to the visit of Pope Francis to Dublin from August 21-26. He has frequently stressed the Catholic Church's teaching on abortion and has spoken vehemently of the unborn child's right to life.