Opponents of marriage equality have so far outspent the yes campaign by about five-to-one in television ads in the Australian same-sex marriage postal survey campaign, according to research by an advertising analytics firm.

Ebiquity found the no campaign’s $312,000 and yes campaign’s $64,000 of TV ad spending is dwarfed by the Australian Bureau of Statistics, which has spent $1.7m on the campaign so far.

Both the Coalition for Marriage and Equality campaigns claim their opponent has more cash, but the new figures draw into question the claim that the no side faces a “David and Goliath battle”, as Australian Christian Lobby director, Lyle Shelton, put it at the National Press Club on Wednesday.

Ebiquity analysed free-to-air television ads in the five major metro markets (Sydney, Perth, Brisbane, Melbourne and Adelaide) from the start of the postal survey process on 8 August until Tuesday, 12 September, when the ABS mailed out postal survey forms. Read more via the Guardian