It's the sort of social media campaign that sends shivers through people trying to sell their houses in a flat property market.

Prosper Australia, a little-known group that supports tax reform on land, has ignited a small but growing online push calling for a "buyers' strike" to protest against the high cost of housing.

“I undertake not to bid at auction or negotiate by private treaty to buy real estate until prices moderate, just as they have in all the countries we compare ourselves to,” the Prosper pledge states on its website.

The campaign has jumped to the top of the list of potential campaign ideas on the online activist site GetUp with hundreds of votes added each day over the past week, outpacing support for same-sex marriage and calls for the Australian government not to bow to pressure to outlaw WikiLeaks. It's also bobbing up on Twitter and in other online forums.