Western Australia could be on the verge of abandoning its decades-old "tough on drugs" attitude to illicit substance addiction after both sides of parliament backed a plan to examine the decriminalisation of drugs.

A high-powered parliamentary committee, to be chaired by Greens MP Alison Xamon with representatives from the Labor, Liberal and National parties, will look at "alternate approaches to reducing illicit drug use".

This will include looking at jurisdictions around the world which have decriminalised or legalised drug use.

WA's politicians might be on the verge of putting away the "tough on drugs" rhetoric when examining new drug laws. Credit:File

Ms Xamon said the committee, which would run for 12 months, would also inquire into the decriminalisation of illegal drugs in Portugal.