A heterosexual couple have won their legal bid for the right to have a civil partnership instead of a marriage.
The Supreme Court unanimously ruled in favour of Rebecca Steinfeld, 37, and Charles Keidan, 41, from London.
The court said the Civil Partnership Act 2004 - which only applies to same-sex couples - is incompatible with the European Convention on Human Rights.
Campaigners urged the government to "seize this opportunity" and allow all people to access civil partnerships.
In a civil partnership, a couple is entitled to the same legal treatment in terms of inheritance, tax, pensions and next-of-kin arrangements as marriage.
The couple said the "legacy of marriage" - which "treated women as property for centuries" - was not an option for them.
Since March 2014, same sex-couples can chose whether to enter a civil partnership or to marry. This has not been possible for mixed-sex couples, which led Ms Steinfeld and Mr Keidan to argue that the law was discriminatory.
Why we want a civil partnership
Why choose civil partnership over marriage?
This ruling overturns a previous judgement made by the Court of Appeal, which rejected the couple's claim, in February of last year.
"We want to raise our children as equal partners and feel that a civil partnership - a modern, symmetrical institution - sets the best example for them," they explained.
What does a civil partnership offer?
Legal and financial protection for both parties in the event of the relationship ending
It is free of the religious connotations of marriage
Some object to marriage as an institution and its associations with property and patriarchy
The judgement does not oblige government to change the law, although it does make it more likely that the government will now act, the BBC's legal correspondent Clive Coleman explained.
The couple will later go to Whitehall to deliver a letter to Equalities Minister Penny Mordaunt.
Martin Loat, chairman of the Equal Civil Partnerships campaign, said: "There is only one possible way forward - giving everyone the right to a civil partnership - and we urge the government to seize this opportunity to announce it will end this injustice now."
More than 130,000 people have signed an online petition in support of civil partnerships for everyone.

https://www.bbc.com/news/uk-44627990