The government has been accused of undermining marriage through its new proposals to open up civil partnerships to heterosexual couples.
Ministers said the move, announced at the Conservative Party conference in Birmingham, was an “important step forward for equality”.
It follows a Supreme Court ruling that legislation on civil partnerships, which are currently open only to same-sex couples, was in breach of the European Convention on Human Rights.
Rebecca Steinfeld and Charles Keidan (pictured above), a couple from London had taken their case to the Supreme Court.
The Government said extending them to opposite-sex couples in England and Wales would provide greater security for those who wanted legal recognition for their relationship but did not want to get married.
In a statement Mrs May said: “This change in the law helps protect the interests of opposite-sex couples who want to commit, want to formalise their relationship but don’t necessarily want to get married.
“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.”
Christian charity CARE has criticised the move.
In a statement, spokesperson James Mildred said: “Coming off the back of the Government’s rush to implement no fault divorce, coupled with today’s announcement it’s a double whammy.
“There is a real narrative developing that this is a Government unwilling to back marriage.
“We recognise that for some civil partnerships reflect a genuine desire to commit. We think though that marriage is the gold standard of commitment.