Senate powerbroker Nick Xenophon has accused social media giant Facebook of not acting fast enough to stamp out fake news.
Four of the world's largest companies have been under investigation by the ATO, an inquiry has heard.
Defence Minister Marise Payne has not ruled out returning to a combat role as part of a renewed strategy to beat back the resurgent Taliban.
Prime Minister Malcolm Turnbull has said he deplores the hurtful language being used against people and insists the vast majority of Australians are bringing respectful views to the public debate about same-sex marriage.
The Turnbull government has asked the High Court to hear questions over the validity of MPs within the next month.
Angry Coalition MPs are blaming the citizenship fiasco and the marriage survey for another hit in the polls.