The editor of the influential ConservativeHome blog has added his support to the Out4Marriage campaign, recording a video in favour of allow gay couples an equal right to marriage.

Having previously formed the Conservative Christian Fellowship and the Centre for Social Justice, Tim Montgomerie founded the Tory blog in 2005, from which point the site’s readership has grown to reflect and influence party views.

Earlier this year, he wrote of his support for the government’s plan to allow gay and straight couples equal access to marriage and a way of combining “gay rights with religious liberty”. He added that the government had said it would “protect the rights of religious groups to hold firm to their view that marriage must remain between a man and a woman”.

Mr Montgomerie said: “For me marriage is one of the most important Conservative institutions, it binds people together almost like no other institution that man has ever created. It doesn’t just bind together the people that are part of it, but it binds together their friends, their relatives and their loved ones. It’s an institution that builds the best in society. It’s a compassionate, caring, inclusive institution and I want as many people as possible to be part of it.

“That is why I’m Out4Marriage, Out4Marriage for gay people as well as for straight people. And I hope that this is the beginning of building a society where people feel part of that institution and where Government feels much more able to support it. So once again, I’m Out4Marriage, are you?”

Last week, Home Secretary Theresa May recorded a video, saying: “Marriage binds us together, it brings stability, I think marriage makes us stronger. But I believe also in commitment and in fidelity in marriage, I think these are good things and we should enable them to flourish.

“That’s why I believe if two people care for each other, if they love each other, if they want to commit to each other and spend the rest of their lives together then they should be able to get married, and marriage should be for everyone, and that’s why I’m coming Out4Marriage.”

Supporters of the Out4Marriage campaign include Sir Richard Branson, the Virgin founder; The Saturdays girl groupJack Straw, the former Foreign Secretary; David Walliams, the  Britain’s Got Talent judge; Yvette Cooper, the shadow Home Secretary; Caroline Lucas, the leader of the Green party; Lynne Featherstone, the Lib Dem Equalities Minister; Peter Tatchell, the  gay rights campaigner; Lord (Chris) Smith), the Advertising Standards Authority chairman and Rabbi Ariel Friedlander.