A couple will launch a Supreme Court bid in an effort to open civil partnerships to heterosexual partners.
The pair, Charles Keidan and Rebecca Steinfeld, argue that they should not have to get married to have the same legal rights as those who do.
They lost a Court of Appeal ruling this week, after three judges ruled that the Government needed “more time” to decide if civil partnerships should be extended to heterosexual couples.
Lady Justice Arden said in her judgment that the ruling potentially violates the couple’s rights.
The couple have set up a crowdfunding initiative to help cover the costs of litigation.
Ms Steinfeld said: “We are very disappointed because we have come so close and the judges agreed on so much. It was a split decision, and we lost on a small technicality.
“The court says the government needs a little more time, but we feel they have had enough and in the interim there will be people who suffer material detriment because of this.”
She added that the pair had huge public backing behind them.
“The writing is on the wall and we hope the government will act voluntarily to extend this to everyone – all it would take is to use the forthcoming Queen’s Speech to remove six words from the Civil Partnership Act, which state civil partnerships “must be of the same sex”. But if they do not, we will continue our campaign,” she said.