A campaign to legalize gay marriage in Britain begins next month with eight couples challenging the government's unions laws.

During an eight-week period ending on December 14, a gay or straight couple will apply for a union they are currently not eligible for.

Gay couples will request a civil marriage, and straight couples will seek to enter a civil partnership. Great Britain recognizes gay and lesbian couples with civil partnerships, not marriage. Such unions are off-limits for straight couples.

Peter Tatchell, of the gay rights group OutRage!, told UK paper the Guardian that the campaign aims to overturn bans on gay marriage and heterosexual civil partnerships.

If officials at British register offices deny the requests, the group plans to sue the government, Tatchell said.

“Don't get me wrong, civil partnerships are an important advance,” Tatchell wrote in a recent post at the group's blog. “They remedy many – though not all – of the injustices that used to be experienced by lesbian and gay couples. But they are not equality.”

“The homophobia of the ban on same-sex civil marriage is now compounded by the heterophobia of the ban on opposite-sex civil partnerships.”

A majority of Britons (61%) support the legalization of gay marriage, a June 2009 poll found.