Instead, they are among more than 23,000 Australians stranded overseas due to passenger caps on international flights.

Ms Gillespie, of Whitebridge, and Mr Brocklesby, from Orange, had been working in childcare in the UK for 18 months when the pandemic hit, but their work and rental commitments didn't end until July.

"We did consider coming home in March when the world was turned upside down, but we had responsibilities - a home, a job," Ms Gillespie said. "If I knew that I would be in this situation today I would have come home back then. But nobody knew what was coming.

"At the time, we had conflicting and confusing messages from the Australian Government. We were told to 'just come home', then next it was 'just stay put and wait'."

By July, the airlines still flying to Australia were charging "exorbitant" fares for tickets. They had bought tickets home for September as it was the first fare they could afford. But their visas were due to expire in August.

"I no longer have the right to live and work in the UK, so I am a 'tourist' until I can get home," she said.

"Air bridges were being introduced between the UK and Europe, and as visa extensions weren't clear at that time, we decided to fly into Europe instead of being penalised for overstaying in the UK."

They heard the stories of Australians getting bumped from their flights with no notification from the airlines.

"Almost a week out from our flight, we found ourselves in the same situation," she said. "Now we can't get home until the 25th October, according to Qatar Airways - and that's in the hope that the flight caps are lifted and we don't continue to get bumped.

"I am now jobless, homeless and stuck in between countries until we can get home. My savings won't last long. There are people worse off than me, but we all should be able to come home."

While National Cabinet has agreed it needs to increase the 4000-person weekly cap on passengers arriving from overseas, Prime Minister Scott Morrison said NSW had been doing "all the heavy lifting" and the state's quarantine was at capacity.

They were looking at whether travellers could be diverted to other "ports".

The Department of Foreign Affairs and Trade is offering loans to eligible Australians to cover accommodation and daily living expenses until they can return.

"If they can pull $5 million into providing these loans, why can't that be put towards helping us get home and into quarantine instead? Aren't the caps in place to ease the pressure of quarantine costs?" Ms Gillespie said.

"For me, this was an adventure of a life time - living and working in London and travelling.

"I was supposed to return home to my family and friends ... a new nephew I am still yet to meet. My best friend's wedding next month.

"What was an adventure of a lifetime is slowly becoming a nightmare, with no end in sight.

"I plead with the Australian government to lift the caps to allow more of us to return home sooner."