Ireland's Taoiseach has urged the country to trust women as he launched his bid to overturn some of the strictest abortion laws in Europe.
The Republic has a near-ban on terminations, and nine women travel abroad every day for the procedure.
The May 25 referendum is the latest in a series of liberalisation measures which has seen divorce and same-sex marriage legalised.
Taoiseach Leo Varadkar said: "I am calling for a Yes vote because I trust women."
He said change represented a measure of compassion, an end to the chill factor facing those who want the procedure.
The leader also rubbished suggestions reform would see the number of abortions rocket, and claimed those on that side of the argument thought very little of women.
Abortion is currently only available when a mother's life is at risk, but not in cases of fatal foetal abnormality, rape or incest.
Parts of Ireland are becoming increasingly secular but the Catholic church is among those campaigning for a No vote, those who argue that a baby's life is sacrosanct.
The leadership of the largest party in Ireland's coalition Government, Mr Varadkar's Fine Gael, is pressing for Yes.
The ballot will be on whether to retain or repeal the Eighth Amendment of the constitution, which means the life of the woman and her unborn child are seen as equal.
Draft legislation proposes unrestricted abortion access be made available to women who are up to 12 weeks pregnant.
Fine Gael officially launched their Yes campaign at a theatre in Dublin on Saturday.