Corporates support gay marriage

Corporate giants McDonald's, Twitter and the big four banks are among 154 of the nation's biggest household brands to declare their support for same-sex marriage.

The companies - which also include Telstra and Qantas - feature in full-page ads in weekend newspapers calling for marriage equality.

They've also signed a joint letter calling on federal parliament to act.

Australian Marriage Equality, which organised the ad, said the outpouring of support showed how important marriage equality was for workplace equity, jobs in the wedding sector and Australia's international reputation.

"The message is clear: the country is ready for change," director Rodney Croome said.

The ad was paid for by contributions from featured firms.