West Australian treasurer Ben Wyatt will walk away from politics at the state election, casting more doubt on the future of proposed changes to Aboriginal heritage laws crucial to the future of the mining industry and protection of culturally significant sites.

Mr Wyatt, one of Australia's most prominent and respected Aboriginal politicians, is the architect of the proposed laws, which have taken on greater importance in the wake of Rio Tinto's destruction of 46,000-year-old rock shelters at Juukan Gorge in May.