It is the term du jour, thrown around by everyone from Donald Trump to Australian politicians, unhappy with how a particular news story paints them.

But now Labor senator Sam Dastyari believes he has the numbers to have the Senate investigate "fake news" and its impact on Australia to identify who is responsible and how to combat it.

It is understood internet giants Facebook and Google would be called to discuss how they are combating the phenomenon.

The inquiry, for which terms are still be negotiated, would look at identifying groups most vulnerable to fake news, measure the impact on traditional journalism, and assess the liability of online advertisers and "click-bait" in spreading the hoaxes.