Qantas has cancelled all flights into and out of Sydney, Melbourne and Canberra on Wednesday as the Chilean ash cloud wreaks havoc.
The decision followed the airline, along with Virgin, Jetstar and Tiger, halting services to Sydney, Canberra and Adelaide on Tuesday, stranding tens of thousands of passengers.
"We estimate that we will be cancelling in excess of 200 flights on Wednesday," Qantas spokeswoman Olivia Wirth told reporters.
"The experts say we simply won't be able to operate in this situation."
It first entered Australian and New Zealand airspace just over a week ago, causing some airlines to ground all flights to affected areas while others chose to divert their planes under and around the plume.
Federal Transport Minister Anthony Albanese says the mass cancellation of flights out of mainland Australian cities is an extremely rare occurrence but safety must come first.
Airlines have cancelled domestic flights across the country as a volcanic ash cloud from Chile re-enters Australian airspace.
Qantas and Jetstar canned domestic flights in and out of Sydney from 3pm.
Virgin passengers face lengthy delays with domestic flights to cease from 4pm, while Jetstar has cancelled all flights from Adelaide.
Tiger Airways has cancelled all domestic flights
Mr Albanese says the Bureau of Meteorology has indicated that Canberra and Sydney airports will be affected by the ash cloud for up to another two days, but the situation isn't set in stone
Adelaide will be affected for about 24 hours while Melbourne should expect two full days of interruptions.
Brisbane Airport issued the warning on Tuesday, urging passengers to stay in touch with their airlines.
The ash cloud is denser and larger than that which caused widespread flight disruptions last week.
It is also predicted to linger longer over southeast Australia.
Virgin and Tiger say flights to and from the Gold Coast are also being affected by the cloud.
A total of 12 Gold Coast flights will be cancelled.
Jetstar will cancel all flights between the Gold Coast and Sydney from 3pm (AEST) and to and from Canberra from noon.
All flights to and from Adelaide have also been cancelled.
Virgin will also cancel Gold Coast flights to and from Canberra from 1pm.
