Simon Coveney had previously expressed his discomfort with the Government's proposals
In a surprise move, the Tánaiste has backed abortion for up to 12 weeks into a pregnancy.
Simon Coveney had been seen as an opponent of the proposals being debated at the Cabinet table about potential new laws if the Eighth Amendment is repealed.
It's a shift in position that could have a major impact on the abortion referendum campaign.
Minister Coveney had expressed his discomfort with the Government's proposals for abortion without restriction for up to 12 weeks, and was expected to campaign against them.
However, writing in the Irish Independent this morning, the Foreign Affairs Minister says he has changed his mind.
He says he still has concerns that people who are raising legitimate questions about the unborn are being dismissed as "dinosaurs or anti-women".
He stressed: "I could never support a law that allows for late-term abortions. The Government will move to close off any suggestion of that happening by stating that a baby who could survive outside the womb will not be aborted in any circumstance."
The Health Minister and senior clinicians have reassured the Tánaiste on a number of issues he felt strongly about.
Minister Coveney says he also feels satisfied that the 12 weeks limit will not allow for the testing for disabilities.
In his piece this morning, the Tánaiste says he supports allowing abortion pills up to 12 weeks gestation as long as the move "is coupled with strict guidelines" when abortions are requested.
He suggested: "If we do nothing, we know pills will continue to be purchased online and taken without medical advice or supervision. We cannot knowingly allow this to continue, given the dangers involved."
It is a potentially significant change of heart, given that some expect there will be attempts to change the legislation from 12 weeks to 10 weeks if the Eighth Amendment is repealed and it comes before the Oireachtas.
Additional reporting by Stephen McNeice