Civil partnerships are to be extended to heterosexual couples, the prime minister has said, following a Supreme Court ruling earlier this year that existing discrimination is unlawful.

Theresa May said a change in the law would protect the interests of opposite-sex couples who want to formalise their relationship without getting married.

In June, family solicitors urged the government to extend civil partnerships to couples of the opposite sex after the Supreme Court ruled in Steinfeld and Keidan v Secretary of State for International Development that there was no justification for the ongoing discrimination since legislation was introduced allowing same-sex couples to marry.

The Civil Partnership Act 2004 enabled same-sex couples to obtain legal recognition of their relationship by registering a civil partnership at a time when they were not allowed to get married. The Marriage (Same Sex Couples) Act 2013 allowed same-sex couples to get married or convert their civil partnerships into marriage. 

The prime minister told the London Evening Standard today: ’As home secretary, I was proud to sponsor the legislation that created equal marriage. Now, by extending civil partnerships, we are making sure that all couples, be they same-sex or opposite-sex, are given the same choices in life.’

In a joint statement, Steinfeld and Keidan welcomed the PM’s pledge, but also called for a firm date for the reform.

Graham Coy, a senior partner at Stowe Family Law in London, said: ’This is a very welcome development and will provide protection to those who live together but do not want to marry. What it will not do is give any protection to the increasing number of couples who do live together but do not want to marry nor enter in to a civil partnership. That anomaly still needs to be dealt with.’

However Mark Harrop, senior associate in the family team at Collyer Bristow LLP said: 'This is being presented as a victory for equality, but may actually present a huge own goal for those who want better rights for cohabiting couples. Civil partnerships are marriages in all but name – there is no reason to think that many people will opt for them who would not otherwise have got married. What are really needed are better rights for those 3.3 million cohabiting couples who have not opted in to either arrangement; sadly this announcement is likely to see such reform kicked further into the long grass.'

Law Society president Christina Blacklaws said: 'We have been in favour of extending civil partnerships to opposite sex couples for a long time. That’s because we support the principle of non-discrimination on grounds of sexual orientation. So we’re pleased to see the government is responding to recent judge-led decisions highlighting the need for changes in the law to reflect 21st century society in this country.

'The law needs to catch up with, and reflect, the multiple ways in which people choose to live their lives today. We are absolutely in favour of a review of all areas of the law affecting civil and religious contracts/marriages/partnerships.’