The High Court action being taken by Katherine Zappone and Ann Louise Gilligan for recognition of their marriage in Ireland is the first step towards attaining full equality in Ireland, according to Senator David Norris.
Mr Norris was speaking at a fundraising event for Ms Zappone and Ms Gilligan at the Mansion House, Dublin, yesterday, which was attended by over 200 people.
"We decided to seek justice for ourselves and those who share our sexual identity because enough is enough. We live in an Irish society that negates and diminishes our life-long love and partnership," Ms Zappone told the assembled guests.
Ms Zappone and Ms Gilligan were married in a civil ceremony in Canada in 2003. Through legal action the couple are seeking recognition of their Canadian marriage in Ireland and to have the Revenue Commissioners treat them in the same way as a married couple under the tax Acts.
Their case is currently awaiting a date for hearing.
A website, www.kalcase.org, to encourage public debate on issues surrounding the couple's case was also launched at the Mansion House yesterday.
Eoin Collins, director of policy change with the Gay and Lesbian Equality Network (Glen), said yesterday a "significant" number of gay and lesbian people in Ireland would like to marry. "This case will test conventional wisdom that gay and lesbian people are not equal under the Constitution. We very clearly are."
Mr Collins said that the recognition for tax purposes of same-sex unions was supported across the political board. "Minister Michael McDowell has spoken twice about his commitment to equality. Bertie Ahern has also spoken about a need for equal recognition," he said.
Ailbhe Smyth, head of Women's Studies at UCD and chair of the National Lesbian and Gay Federation, said she was "optimistic" about a positive outcome in the couple's case. " It's really about equality and status for lesbian and gay couples," she added.