Manning, whose sentence was commuted by President Obama in January 2017, just before the Trump inauguration, now makes her living as an international speaker and activist.

She recently applied for a visa to come to Australia for paid speaking engagements in Sydney, Brisbane and Melbourne. Her first appearance, as part of the Antidote festival at the Sydney Opera House, is scheduled for Sunday.

That now appears unlikely to proceed given the Federal Government is considering whether or not to deny her a visa. Manning has been issued with a "Notice of intention to consider refusal of your visa application".

The Home Affairs Department said Manning's eligibility to enter Australia was in doubt because of her criminal record.

Obama only commuted her sentence; she retains her convictions for espionage and theft.

The issue of the "Notice of intention" has caused outrage in some quarters with Antidote organisers, lawyers, journalists and civil rights and free speech activists all condemning the move as tantamount to an act of censorship.

Her defenders argue that Manning's actions had a positive effect in that they exposed war crimes and human rights abuses during the wars in Iraq and Afghanistan.

This included sending video of the Granai airstrike, in which between 86 and 147 Afghan civilians were killed in an attack by a USAF B-1 bomber near Herat on May 4, 2009, to Wikileaks.

Other people, including former army officer, NSW RSL president and non-resident fellow at the United States Study Centre, James Brown, are critical of Manning's actions and have defended moves to ban her from entering the country however.

Brown says Manning is a "text book example" of why there needs to be a character test for people wanting to enter Australia as visitors.

"Coming into Australia as a non-citizen is a privilege, not a right," he said. "Someone who has a substantial criminal record shouldn't enjoy that right, and particularly someone who has worked to undermine our national interest and the security of our troops."

Brown, who says people would have died as a result of Manning's actions, doesn't see this as a freedom of speech matter: "No-one is saying you shouldn't read her books or her columns... [but] we have the right to determine who comes into Australia."

An interesting counterpoint to Manning is Jordan Belfort, the so-called "Wolf of Wall Street" who spent 22 months in prison in the US after pleading guilty to fraud and stock market manipulation that resulted in stock holder losses of more than $200 million.

Belfort has visited Australia as a paid speaker on two separate occasions.

Manning, like Belfort, does not appear to be somebody whose presence in this country represents a danger to the public. There is no risk she will re-offend, incite violence, encourage terrorism or steal documents.

If Manning is banned from entry the Government will find itself under pressure to explain why a premeditated fraudster is okay but a woman regarded by many as a whistleblower, a hero and an activist is not.