International travellers who fly to Australia without proof of a COVID-19 vaccination will be required to quarantine at their own expense.

That’s if they can get on a flight, after Qantas signalled anti-vaxxers will be banned from flying on their aircraft fleets.

Prime Minister Scott Morrison signalled the tough new rules on Melbourne’s Kiss FM radio on Wednesday.

“We’re obviously working through those issues now, but look, where people have the choice of two weeks of quarantine or being vaccinated, I think that will be an incentive, unless there’s a genuine medical reason why,” Mr Morrison said.

The cost of quarantine can run to several thousand dollars for the fortnight in a hotel, depending on what city you quarantine in.

“We’ve got a lot of those issues to work through and so do all the other countries,” Mr Morrison said.

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Health Minister Greg Hunt has also hinted at the vaccination passport plan but stressed the policy was still under discussion.

“So there’s been no final decision, but we’ve been clear, and I’ve given guidance previously that we would expect that people coming to Australia while COVID-19 is a significant disease in the world will either be vaccinated or they will isolate. That’s early guidance,’’ he said.

“The likely course of events during 2021 is if somebody comes to Australia and a vaccine is widely available, either they’ll be vaccinated with verification or they’ll have to quarantine.”

Qantas CEO Alan Joyce has signalled that proof of COVID-19 vaccination will be a non-negotiable condition of international air travel.

On Monday night, he told A Current Affair host Tracy Grimshaw that as soon as a vaccine becomes available it will be a condition of travel.

“For international travellers, we will ask people to have a vaccination before they get on the aircraft,’’ he said.

“Certainly, for international visitors coming out and people leaving the country we think that’s a necessity.”

If anti-vaxxers want to try alternative airlines, Mr Joyce predicted they won’t be travelling far.

“I think that’s going to be a common thing talking to my colleagues in other airlines around the globe,’’ he said.

Prime Minister Scott Morrison has previously suggested vaccination will be “as mandatory as you can possibly make it” before walking those comments back in recent months.

“There are always exemptions for any vaccine on medical grounds, but that should be the only basis,” he said in August.

But just hours later, Mr Morrison told listeners on Sydney radio station 2GB that the Government would not make vaccination mandatory.

“It’s not going to be compulsory to have the vaccine,” he said.

“I mean, we can’t hold someone down and make them take it.”