Same-sex marriages are now celebrated all over the UK. They are a core part of the UK’s culture, communities and institutions. 

Passing legislation to introduce same-sex marriage was a landmark moment – for many couples personally, but also for the wider lesbian, gay, bisexual, trans plus (LGBT+) community. It marked an important step in addressing the UK’s past legal discrimination against same-sex couples, building on the achievements of a long history of campaigners who worked to expand LGBT+ rights. 

This case study looks at how the government passed the Marriage (Same Sex Couples) Act 2013. It examines the policy’s journey, from a campaign aim of LGBT+ rights groups, to a contested issue in the 2010 general election, to official government policy, and finally to legislation that introduced same-sex marriage rights in England and Wales, while accommodating many of the concerns of those who remained opposed. 

It draws on a policy reunion at the Institute for Government held in March 2023, which brought together officials, ministers, LGBT+ rights campaigners and representatives from religious organisations to discuss what made the policy making process for same-sex marriage a success, and what lessons the government can learn from it to inform future policy making. It also draws on interviews and a literature review.