Member for Hughes Craig Kelly has quit the Liberal Party.
Mr Kelly will immediately move to the crossbench as an independent.
The Hughes MP indicated in a speech in parliament today his reasons for quitting the Liberal Party.
"Over the past several months, I have been subject to a slander and smear campaign when my goal was only to save lives," he said.
"My goal was to ensure my constituents and, in fact, all Australians were not being denied access to medical treatments if their doctor believed those treatments could save their life.
"Therefore, if I am to continue to act in line with my conscience and my principles and the oath I took in becoming in becoming a member of this parliament and continue to speak fearlessly and faithfully representing my constituents, I have no alternative other to take the action that I have. "
Mr Kelly handed his letter of resignation to the Prime Minister during today's party-room meeting.
Mr Kelly said he would continue to provide supply for the government.