A gay couple who got married in Canada should not be regarded as a married couple under Swedish law, a court has ruled.

Lars Gårdfeldt and Lars Arnell lost their case against the Swedish tax authority.

The couple, who are both Church of Sweden priests, claimed the decision to classify their Canadian marriage as a civil partnership was discriminatory.

Sweden highest court, the Supreme Administrative Court, said that a Swedish law from 1987 defines marriage as between a man and a woman and therefore the tax authority was correct to classify the overseas same-sex marriage as a civil partnership.

The gay couple had argued that “the tax authorities can make an exception for a marriage where one party is under-age but not for homosexuals,” The Local reports.

If they had won the case it could have led to a de facto legalisation of same-sex marriage.

Sweden’s Prime Minister has pledged to introduce a ‘gender neutral’ marriage law next year.

In January 2007 the Church of Sweden, which was disestablished in 2000, began offering religious blessings to gay unions and actively welcomed LGBT clergy.

Last year the Church agreed that marriage and partnership were equivalent forms of unions.

It recommended however that the term “marriage” be referred only to heterosexual couples.

The Swedish Church, a Lutheran branch of Christianity with more than 7 million members out of a population of 9 million, had been asked to express its opinion on the matter directly by the government, which intends to modify the 1987 law defining marriage as an union between man and woman.

While there is strong support for gay marriage, the measures to introduce it have still not come before Parliament.

Gay and lesbian couple can register their partnership through a civil ceremony, a process introduced in 1995 which gives same-sex couples the same rights as married couples.

A poll for the Sifo Institute published in January found that 71% of Swedes think gay people should be allowed to marry.

Six of the seven parties represented in Sweden’s parliament are in support of gay marriage with only the Christian Democrats, a junior member of the four-party coalition, opposing it.

The opposition Social Democrats, Greens and Left party claim the government has had ample time to bring forward legislation.

Last month Swedish Prime Minister Fredrik Reinfeldt said:

“The coalition government has agreed that we will present a basic marriage bill to parliament.

“The three parties in favour of a gender neutral marriage law will then present an accompanying motion seeking to have such a law in place by May 1st 2009.”

The new law would allow church weddings, though clergy can opt out of performing gay ceremonies.