FORMER PM John Howard is back on the campaign trail in Adelaide today after yesterday declaring marriage equality is "nonsense".

Mr Howard, who is in Adelaide bolstering support for the Coalition, this morning set a cracking pace as he took to the Torrens for his famous morning walk.

After his walk Mr Howard was back on the roads, heading up to Gawler, in the seat of Wakefield, where the Liberal party hopes to make ground with candidate Tom Zorich.

Yesterday, while in Hindmarsh, which is sitting on 50/50 in the polls, he did a good old-fashioned shopping-mall walk, where he had a ridiculous number of selfies taken with strapping young lads.

He may have single-handedly won the seat for local Liberal candidate Matt Williams - in 2004 Labor wrested Hindmarsh from the Liberals with just 108 votes.

media_camera John Howard walks through Westfield West Lakes. Picture: Simon Cross

Mr Howard said he was against gay marriage and that "the best environment to raise children is in an ordinary, orthodox, heterosexual marriage".

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Asked whether he thought there should be a conscience vote, he said that was a matter for the party.

"But if you're asking my view … I think this whole argument that it's marriage equality is nonsense," he said.

media_camera Another selfie: John Howard in Westfield West Lakes with Senator Simon Birmingham and Liberal candidate for Hindmarsh Matt Williams. Picture: Simon Cross

"The present (situation) doesn't discriminate against people, it just recognises not only a long-standing attitude and custom but also recognises that anything we can do to preserve current notions of marriage are more likely on balance to provide the best environment for raising children."

His comments come in stark contrast to Prime Minister Kevin Rudd's spirited defence of gay marriage against a pastor on ABC TV's Q &A last night.