The first civil partnerships for opposite-sex couples have been taking place today.
As the country prepares to ring in the New Year, thousands of heterosexual couples were formalising their relationships with a civil partnership.
Same-sex couples have been able to enter into a civil partnership since 2005. The Government changed the law to make it possible for heterosexual couples to choose a civil partnership as an alternative to marriage.
The change gives them access to the same tax benefits, pensions and inheritance rights as married couples. It also gives joint parental responsibility for children born to civil partners.
The Government said that civil partnerships were "not intended to compete with marriage but rather to provide an alternative option for those couples who do not wish to marry but want legal certainty and stability for their families".
Minister for Women and Equalities, Liz Truss, said: "I am proud that we have helped give thousands across the country the option to have a civil partnership and celebrate their union in a way that works for them."
The change has been criticised in the past by Colin Hart, Director of the Christian Institute.
"While ministers present this as a credible alternative, civil partnerships are simply marriage-lite," he said.