Australia's first mainstream advertising campaign for same-sex marriage begins today with a series of ads in the online edition of the Age.

The ads aim to encourage heterosexual supporters of same-sex marriage to send submissions to the current Senate inquiry into marriage equality.

Australian Marriage Equality spokesperson, Peter Furness, said the ads take the campaign for same-sex marriage to a new level.

"Our ads aim to reach out to the 60% of Australians who support same-sex marriage, most of whom are heterosexual", Mr Furness said.

"The Government needs to hear that equality has the support of most Australians, not just same-sex partners."

Four different ads will appear on the Age website beginning tomorrow and ending next Tuesday.

The ads are an initiative of Australian Marriage Equality and sponsored by Parents and Friends of Lesbians and Gays (Brisbane).