Jose Luis Rodriguez Zapatero, the twice-elected prime minister of Spain, has lauded gay marriage as a great achievement.

When asked in a television interview for examples of the best and worst of being prime minister, the 50-year-old Zapatero gave gay marriage as an example of one of the best things he's done during his two terms.

“The best thing is that you can change things, and the lives of people,” he said on Los Desayunos de TVE. “I'll always remember, for example, that with the gay marriage law … There have been many, many gay people who have approached me and thanked me: 'Never forget, you've changed our lives, you've made us happy.'”

In his bid to win a third term as prime minister, Zapatero will face Mariano Rajoy, the president of Spain's conservative Partido Popular (PP), next year.

Rajoy – and his party – oppose the country's five-year-old gay marriage law.

Pope Benedict XVI has urged Roman Catholics to oppose Zapatero's socialist government and its liberal reforms, which include fast-track divorce, gay marriage and easier access to abortion.