The motor industry warns that changes to the consumer law for online auctions could stop goods being sold by auction altogether.
The Government is reviewing consumer laws and is considering whether the Consumer Guarantees Act should apply to online auctions.
Trade Me says it has lobbied for five years to get the Consumer Guarantees Act to cover online auctions.
It says people who buy goods at a fixed price or use the 'buy now' option have consumer protection, but those who buy by auction do not.
However, the Motor Trade Association says making online auctions by traders subject to the Act could extend to traditional, offline auctions which could put traders off using auctions altogether.