Football is the latest battleground for opponents of gay marriage who are targeting St Kilda and Sydney as part of a campaign to derail the AFL's first Pride match.

Flyers were left on spectators' cars outside the VFL game between Sandringham and Footscray last weekend, with the heading: "Children deserve a mother and father."

Anti-gay marriage protesters have targeted the AFL's first Pride game between St Kilda and Sydney.

The leaflets read: "Saints, Swans and the AFL. Who do you think you are? By support for the same-sex attracted agenda with a Pride Game you are saying that you don't support natural marriage.

"Two men cannot replace a child's mother. Two women cannot replace a child's father."