Stringent government control and oppressive social media platforms are forcing Australians to self-censor themselves, according to controversial media personality Katie Hopkins.

Ms Hopkins, who is known for her strident support of Donald Trump and Boris Johnson, says social media giants like Twitter and Facebook often punish those whose views fall out of the mainstream. She told Sky News freedom of speech, which was once the bedrock of democracy, "no longer exists" in many western nations.

"Frankly, no one would defend freedom of speech to their death because we (Australia and the UK) don't have it anymore," she said. "Good Australians that I know and I love, they self-censor everywhere they go because they can no longer speak about how they think or how they feel. "It's the mechanism of control."