Groundbreaking public health initiatives such as plain cigarette packaging would be assigned to the past if the federal government signs up to leaked versions of a proposed trade pact between Pacific nations, according to academic modelling.

A health impact assessment of the Trans Pacific Partnership Agreement indicates that some provisions have the potential to increase the cost of medicines and limit the government's ability to regulate in areas such as smoking, alcohol and junk food.

Could plain packaging be scrapped? Credit:Nic Walker

A draft version of the agreement, published by Wikileaks, has provisions for investor-state dispute settlement procedures which would enable foreign companies to sue governments that legislated policies that affected their business.

Similar investor-state dispute settlements make exemptions where there is clear evidence of a public health benefit.