The Morrison government is bracing for a new round of cabinet resignations ahead of the May election, with focus shifting to the future of the Coalition's two most senior defence figures.

Defence Industry Minister Steve Ciobo is preparing to announce his retirement as soon as Friday, potentially bringing the total number of departing government frontbenchers to four.

Defence Minister Christopher Pyne has been in Parliament for 26 years. Credit:Photo: Alex Ellinghausen

Many are also sceptical of Defence Minister Christopher Pyne's repeated declaration that he "intends" to recontest the election, pointing to Julie Bishop's use of the same language for months prior to her decision last week to retire from politics.

Mr Pyne, who has been in Parliament for 26 years, is one of the Liberal Party's leading moderate figures and is a close supporter of former prime minister Malcolm Turnbull.