Supermarket giant Coles faces accusations from an irate federal government that its drought-relief milk levy promotion is an "empty media stunt".

Minister for Agriculture David Littleproud savaged Coles on Sunday, claiming there was no guarantee that funds raised from the supermarket giant's temporary milk levy would go back to the farmers who supplied that milk.

Agriculture Minister David Littleproud has hit out at supermarket milk levies. Credit:AAP

Coles has introduced a 30¢ surcharge on all of its three-litre home brand milk products and will collect a levy on these products until the end of the year.

The funds it raises will be distributed via the Dairy Drought Relief Fund, with any Australian dairy farmer affected by drought eligible to apply. Successful applicants can expect to receive funds by January 2019, according to the application form.