Conservative Liberal Senator Cory Bernardi has spoken out against plans to strip suspected Australian terrorists of their citizenship, describing it as "absolutely wrong" and "dangerous power creep".

The Coalition will soon introduce legislation to enable the Immigration Minister to revoke the citizenship of dual nationals who are engaged in terrorism or supporting terror groups.

But Cabinet is considering going further and allowing the minister to also revoke the citizenship of sole nationals if they are eligible to become a citizen of another country.

Forty backbenchers have signed a petition urging Prime Minister Tony Abbott to push ahead with plan, asking for the new laws to be applied "not only to dual nationals but those eligible for the citizenship of another country".

Senator Bernardi said he supported the move against dual nationals but not against those whose only citizenship is Australian.

"As a matter of principle, I think it's absolutely wrong for us to take away citizenship from an individual whose sole citizenship is Australian," he said.

"And particularly be able to do it without any reference to a court of law, at the arbitrary whim of the [Immigration] Minister, I think the principle is entirely wrong.

Senator Bernardi said no-one wanted to stop terrorism and extremism more than he did, but he described the proposal as a "step in the wrong direction".

"The principle that someone with only Australian citizenship can be stripped of that citizenship, without a court of law, by ministerial directive, for an offence, I think is a very dangerous precedent because who's to say the range of offences won't be expanded in the future," he said.

Liberal MP Dan Tehan holds a petition signed by Coalition backbenchers on the citizenship proposals. ( AAP: Mick Tsikas )

"This is the sort of power creep that I think is very dangerous from any Government."

Immigration Minister Peter Dutton supports the plan but told the ABC's 730 program, there could be a downside.

"The most important legal principle for us is that we don't render somebody stateless, so if they can't avail themselves of citizenship elsewhere, then they're stuck as Australia's problem," he said.

"That's the difficulty that we face."

The controversial idea was discussed at length during a heated Cabinet meeting last week.

Fairfax media last week reported several senior ministers raised concerns about the proposal, including deputy Liberal leader Julie Bishop, Communications Minister Malcolm Turnbull, Agriculture Minister Barnaby Joyce, Attorney-General George Brandis, Education Minister Christopher Pyne and Defence Minister Kevin Andrews.

When asked if the document was designed to put pressure on Cabinet ministers he replied, "People can read into it what they like".

"We want to act against dual citizens and... what we're asking the Prime Minister to do is to look at the UK laws and adopt similar laws here in Australia," he said.

"We as backbenchers wanted to let the Government know that we think we should look very seriously at this issue."

Mr Dutton told 7.30 the Government was already taking strong action against suspected terrorists.

"Where they've been involved in criminal activities, terrorist activities now, there might be control orders, there might be activities that the intelligence agencies undertake to monitor what they're doing and the threat that they pose," he said.