Dr Ann Louise Gilligan and partner Senator Katherine Zappone are to issue a fresh legal challenge this week in their fight to be married under Irish law.
The new challenge, which is set to be heard in the High Court, will seek to test the provisions of the Civil Registration Act 2004, which marked the first time marriage was defined in Irish statute as between a man and a woman, and the Civil Partnership Act 2010, which prohibits people who have registered a civil partnership from marrying.
The Constitution does not currently include a definition of marriage, but includes a commitment to equality for all citizens.
Senator Katherine Zappone, a public policy consultant, and Dr Ann Louise Gilligan, an academic, have been together for some 30 years and married in British Columbia, Canada, in 2003.
The couple launched an unsuccessful Supreme Court appeal against the Civil Registration Act 2004 Act in October last and had been planning to proceed with a new challenge.
"It became clear to us that, even if we succeeded with our original case, the provisions within the Civil Registration Act and the Civil Partnership Act would remain. So it became imperative to shelve our Supreme Court appeal and proceed to challenge this Act before the High Court," said Ms Zappone.
Speaking to the Irish Times, she said the couple had been deeply disappointed by the outcome of their Supreme Court appeal but was hopeful the new challenge would succeed.
"We have been at this for almost ten years, looking for the right to marry the person we love. All we want is the right to marry under the Irish constitution," she said.
Her partner also expressed confidence the new challenge would be successful.
"We hold hope and believe that this is the right step towards a positive outcome," said Ms Gilligan. "We remain steadfast in this journey."
The lobby group Marriage Equality welcomed today's announcement.
“This year, 73 per cent of people said they believe marriage equality should be enshrined in the Irish Constitution. That is a clear indication that as a country we are ready to fulfil our constitutional commitment to equality for all," said Marriage Equality director Moninne Griffith.
"We are therefore calling on government to begin work on the constitutional convention as soon as soon as possible and to prioritise dealing with the issue of marriage equality therein.
"This is a key opportunity for the Government to listen to public support and legislate for equality, rather than having the issue decided in the courts," she added.
The Gay and Lesbian Equality Network (GLEN) backed the couple's challenge and said civil marriage should be open to all citizens in a democratic republic.
"Civil marriage, building on the comprehensive civil partnership legislation, is the next incremental step in achieving equality for lesbian and gay couples," said the group's chairman Kieran Rose.
"While civil partnership provides legal protections equal to civil marriage in a wide range of areas, including in social welfare, taxation, inheritance and immigration, civil marriage is the only option that would provide for full Constitutional equality with opposite-sex couples," he added.
