American whistleblower and activist Chelsea Manning is facing the prospect of having her visa application denied by the Australian government just days before her speaking tour – which includes an appearance at the Sydney Opera House – is due to start.

Fairfax Media understands the Australian government is considering refusing entry to Manning, who was released from military prison in 2017, under s501 of the Migration Act.

Chelsea Manning may not be granted a visa in time for her speaking appearance at the Sydney Opera House. Credit:AP

Manning, a former intelligence analyst in the US Army, had been sentenced in 2013 to 35 years prison over the 2010 leak of classified information to WikiLeaks.

In January 2017, then-president Barack Obama commuted her sentence and she was freed the following May.