Maverick government MP George Christensen has quit the Liberal National Party.
Mr Christensen did not intend to stand again for his seat of Dawson at the election due to be called within days.
But he has gone further in quitting the party, announcing it was "effective immediately" on his Facebook page on Thursday.
"My resignation should come as no surprise given the public disenchantment I have expressed about the party's direction," he wrote, citing the net zero climate pledge and "destructive pandemic policies" as concerns.
He said the decision had not come easily given his involvement in the party over almost three decades.
"In 2022, the Liberal National Party - as an extension of the Liberal Party - seems anything but conservative and thus it is no longer my party," Mr Christensen said.
"The party needs to undertake some serious soul-searching.
"If it wants to be all things to all people ... this will see it inhabiting the opposition benches for many a moon."