A lesbian couple are launching a High Court battle to get same-sex marriages legally recognised in Britain.
Celia Katzinger and Sue Wilkinson want their marriage recognised
Celia Kitzinger and Sue Wilkinson were married while living in Canada in 2003 and now want a legal declaration of the validity of their union in the UK.
The couple, from North Yorkshire, said a failure to recognise the legality of their vows breached their human rights.
UK same-sex civil partnerships will become legal in December but the couple said they were a "lesser substitute".
Their application was filed at the High Court on Friday and their case is expected to be heard in 2006.
The new Civil Partnership Act will allow the couple to register their relationship as a civil partnership but not a marriage.
This means they will receive several legal benefits available to heterosexual married couples.
In a statement they said their case was fundamentally about equality.
"We want our marriage to be recognised as a marriage, just like any other marriage in Canada," it read.
"It is insulting and discriminatory to be offered a civil partnership instead.
"Civil partnerships are an important step forward for same-sex couples, but they are not enough.
"We want full equality in marriage."
The High Court is being asked to recognise their Canadian marriage in the same way it would recognise the overseas marriage of a heterosexual couple.
The women intend to argue that failure to do so would constitute a breach of their human rights to privacy and family life and their right to marry.
For an overseas marriage to be recognised in the UK, it must be proved to be legal, recognised in the country in which it was carried out and shown that nothing in the country's law restricted their freedom to marry.
Ms Kitzinger, 48, a professor at the University of York and Ms Wilkinson, 51, a professor at Loughborough University, said their marriage met all requirements.
The couple were married in British Columbia while Ms Wilkinson was living and working in Vancouver.
Civil liberties organisation Liberty are providing legal representation for the women in the case, which is also being supported by the national lesbian and gay campaigning group Outrage!.