A LESBIAN couple from the York area are launching a legal challenge to the UK's refusal to recognise same-sex marriage.

Celia Kitzinger, 48, and Sue Wilkinson, 51, will lodge their case at the High Court in London today, a move that could open the way for removal of the barriers to same-sex marriage.

The couple, who live near York, were married in British Columbia, Canada, two years ago. Celia is a professor of sociology at the University of York.

They say that a failure to recognise the legal validity of their Canadian marriage in Britain constitutes a breach of their human rights.

An application was being filed on their behalf this morning in the Family Division of the High Court in London, formally launching their landmark action.

Their case is expected to be heard in court early next year.

The couple say that under the new Civil Partnership Act, which comes into force in December, they will only be given "second-class status".

They will be able to register their relationship as a "civil partnership" under the new legislation, and receive many of the legal benefits available to heterosexual married couples.

But Ms Kitzinger and Ms Wilkinson believe civil partnership to be both "symbolically and practically a lesser substitute".

They said in a statement: "This is fundamentally about equality.

"We want our marriage to be recognised as a marriage - just like any other marriage made in Canada.

"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."

They said they believed their marriage was worth fighting for.

The court will be asked to recognise their overseas marriage in the same way that it would recognise that of a heterosexual couple.

They will argue that a failure to do so would constitute a breach of their human rights to privacy and family life and their right to marry, and is discriminatory on the basis of their sexuality.

For an overseas marriage to be recognised in the UK it must be shown that the marriage was legal, recognised in the country in which it was executed, and that nothing in the country's law restricted their freedom to marry.

Ms Kitzinger and Ms Wilkinson, a psychology professor at Loughborough University, say their marriage fulfils these requirements even though people cannot legally enter into same-sex marriages in the UK.

They married after the province of British Columbia opened up marriage to same-sex couples.

At the time Ms Wilkinson was living and working in Vancouver. Same-sex marriages were legalised across Canada last month.

The case has been highlighted by civil liberties groups across the country.

The couple are bringing their case with the support of civil liberties organisation Liberty, which is providing legal representation, and with the backing of OutRage!, the national lesbian and gay campaigning group.

James Welch, legal director at Liberty, said: "It is a matter of fairness and equality that they should be treated the same way as any other couple who marry abroad."

Peter Tatchell, of OutRage!, said: "This is a historic challenge to a grave injustice."

Updated: 10:16 Friday, August 12, 2005