The party could quadruple its representation in the Senate, a polling analysis reveals, but the conservative bloc may fall short of holding power.

One Nation leader Pauline Hanson has declared she is fit to serve as prime minister after turning 72 last week, as polling showed Labor falling behind One Nation.

Pauline Hanson has declared she is fit to serve as prime minister, as polling showed Labor falling behind One Nation and the minor party secured another Coalition defector.