Australian opposition leader Sussan Ley, the first woman to head the Liberal Party, is under renewed pressure after the resignation of her shadow defence minister Angus Taylor.

His resignation paves the way for an expected leadership challenge. Local media say he has long been plotting to oust her.

Ley narrowly defeated Taylor in a leadership contest last year after her party's worst ever election loss. Since then, she has been plagued by poor poll numbers and infighting among the conservative Liberal-National coalition.

The coalition, a partnership dating back to the 1940s, has twice split and reunited under her leadership, further undermining her tenure.

Taylor, from the conservative faction of the party, announced his departure from the leadership team but reaffirmed his commitment to continue serving the Liberal Party. He criticized the party for failing to hold the Labor government accountable, stating that it needs to focus on protecting Australians' way of life.

Taylor expressed doubts about Ley's ability to lead the party effectively moving forward, raising questions about potential further resignations from her shadow cabinet.

According to local media, Taylor's allies are expected to request a special party room meeting to consider a spill motion, which would put the party's leadership up for contest. A victory for Taylor would effectively resolve the ongoing uncertainty surrounding Ley’s leadership, which has consistently appeared tenuous.

The coalition recently reunited following a split over hate speech laws proposed by Ley after the Bondi Beach attack in December.

Public sentiment has shifted, with recent polls indicating a rise of the populist One Nation party, further complicating the outlook for Ley and the Coalition, who are grappling with the challenges posed by their significant electoral defeat to the Labor party.