Lesbian couple Rev. Sharon Ferguson and Franka Strietzel plan to challenge the government's unions laws after they were denied a marriage license on Tuesday.

The two women are the inaugural couple participating in the Equal Love campaign, in which eight gay or straight couples 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.

The couple's application was refused at a Greenwich register office in London.

“I'm feeling a little despondent,” Rev. Ferguson, an ordained minister of religion and chief executive of the Lesbian and Gay Christian Movement, said. “Even though we knew we'd be rejected, it hits hard that we've been denied the right to get married.”

The couple, which have been together for over two years, said they want to marry, not enter a civil partnership, which they consider a separate system.

“Like most people in this world, we were brought up to believe that one day we'd fall in love and get married,” Strietzel, a 49-year-old corporate trainer, said. “This is what we want to do and our sexual orientation should not be an impediment.”

Ferguson, 52, told the London Evening Standard that she's received abusive emails over her participation in the campaign.

“We've had a lot of people supporting us, but unfortunately I've also received some abusive emails from people claiming to be Christians who are unhappy with what we are doing,” she said.

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 second couple is expected to apply for a union they are ineligible for next Tuesday.

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