Labor’s national primary vote has dropped five percentage points in a month, falling to 26% in the latest Guardian Essential poll as Anthony Albanese records his lowest approval rating as prime minister.

And despite One Nation’s win in Saturday’s Secret Harbour byelection in Western Australia, the poll showed the national primary vote for Pauline Hanson’s party dropping five percentage points since May. The party recorded a primary vote of 23% in the latest poll, down from a peak of 28%.