Australia's former Prime Minister Malcolm Turnbull on Friday resigned from parliament, a source familiar with the matter said, stripping the government of its one-seat parliamentary majority.

Turnbull last week said he would resign from parliament after he was ousted from office in a bitter party-room contest that ushered in the country's sixth leader in the last decade.

"The speaker of the house of parliament received a resignation letter from Malcolm Turnbull this afternoon," said a source familiar with the matter. The source declined to be named as she is not authorized to talk to the media.