The One Nation leader put the bill to parliament last Wednesday, saying the processors and retailers were being “cold-hearted and cruel” and putting their profits ahead of the viability of dairy farms.
Labor MPs meeting in Canberra on Tuesday agreed to back the legislation.
Senator Hanson also won support from the opposition last week for an inquiry into the re-regulation of the industry, while the government fast-tracked a mandatory code of conduct to take effect in January rather than mid-2020.