The first female leader of Australia's Liberal Party, Sussan Ley, has been ousted after just nine months in the job, losing a leadership ballot to her former shadow defence minister Angus Taylor.

Ley was elevated to the role after the party suffered a resounding defeat in last year's election, but since then has been plagued by poor poll numbers and infighting among the conservative Liberal-National Coalition.

Taylor had announced he would challenge her for leadership of the opposition on Wednesday, ending months of speculation.

In a social media post he said his election on Friday was "an immense honour" and that he looked forward to working with new deputy leader Jane Hume.

Taylor, from the party's conservative faction, won the secret ballot, 34 votes to 17.

Shortly after the results were announced, Ley said that she would resign as an MP and step away "completely and comprehensively from public life".

She told waiting reporters she harboured "no hard feelings" towards the new leader although, in an apparent jab at the infighting she has endured, she added that it was important he get "clear air, something that is not always afforded to leaders".

Taylor, who narrowly lost the 2025 leadership contest to Ley, is a former management consultant who first entered parliament in 2013. He served as a minister under Malcolm Turnbull and Scott Morrison.

Ley's position had never seemed secure. The Liberal-National coalition, a partnership dating back to the 1940s, twice split under her leadership, the first time immediately after the May election and the second time just weeks ago.

A series of recent polls have also shown the populist One Nation Party - which only got 6% of the national vote last year - overtaking the Coalition to take second place behind Labor. Ley's personal ratings have also been poor.

The coalition has largely failed to agree on what caused its crushing election defeat to Labor, which saw the Liberals all but wiped out in the major cities, with disagreements on energy and climate policy in a particular.

Reflecting on her time at the helm, Ley said it had been "very tough" at times but added: "I was part of the early punk rock movement in Canberra, I will continue to find wisdom in one of punk's defining themes, a fearless and honest belief in yourself."