A triumphant Pauline Hanson has declared One Nation is “here for the long haul” after a historic Farrer byelection win that has ignited internal rumblings about Angus Taylor’s leadership just three months into his tenure.

The rightwing populist party won its first federal lower house seat on Saturday night, after David Farley defeated the independent, Michelle Milthorpe.

In a catastrophic result for the Coalition, which had held the seat for its entire 76-year history, the Liberals suffered a swing of more than 30%. Its primary vote sank below 13%, amid what the opposition leader on Saturday night said was an “existential situation for the Coalition”.…