An Irish doctor and a senator are taking a case to the High Court to fight for their same-sex marriage to be identified under Irish law.

Common law partners Dr Ann Louise Gilligan and Senator Katherine Zappone will issue fresh legal proceedings as part of their long term battle to have their Canadian marriage recognized under Irish law, the Irish Times reports.

The case will test the provisions of the Civil Registration Act 2004, which defines marriage as being between a man and a woman,  and the Civil Partnership Act 2010, who prohibits people who have registered a civil partnership from marrying.

The couple, who have been together for 30-years married in British Columbia, Canada, in 2003.

Last October they launched an unsuccessful Supreme Court appeal against the Civil Registration Act 2004.

"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,"  Zappone told the Irish Times.

"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.

Dr Gilligan added: "We hold hope and believe that this is the right step towards a positive outcome.”

"We remain steadfast in this journey."

Kieran Rose of the Gay and Lesbian Equality Network (GLEN) welcomed the announcement.

“Civil marriage, building on the comprehensive civil partnership legislation, is the next incremental step in achieving equality for lesbian and gay couples," he told the newspaper.

"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.

Dr Ann Louise Gilligan and Senator Katherine Zappone pictured with Irish President Michael D HigginsSenator Katherine Zappone