Former UK Prime Minister David Cameron says in a new book that introducing marriage equality in England and Wales is one of the things he is “proudest” of.

The government legalized same-sex marriage in 2014.

In an excerpt from his upcoming book, For the Record, Cameron, who stepped down following the results of the Brexit referendum, said that he lost party members over the issue.

“Equal marriage was one of the most contentious, hard-fought and divisive issues during my times as prime minister,” Cameron wrote.

“We would lose party members; one even came to my surgery and tore up their membership card in front of me.”

“It was an issue that I would worry and even wobble over. But I have absolutely no regrets, and it is one of the things of which I’m proudest,” he added.