Fierce personal attacks and a debate about how to spend Western Australia’s iron ore riches erupted at the official start of campaigning in a state election Labor Premier Roger Cook insists is not a fait accompli.

As he headed to Government House on Wednesday for the issuing of writs in the March 8 election, Mr Cook urged voters to stay the course with Labor, which has held power since 2017 and trounced the Liberals at the last poll four years ago to win 53 of 59 lower house seats.