Virgin Australia is pushing for Sydney Airport to build a rapid-transit system between its terminals after baulking at plans to plonk all of the airline's operations at what is now the international terminal.
The airline has serious concerns about a plan to base its operations and those of its alliance partners at T1, which is likely to derail the airport's aim to remove the split between the domestic and international terminals.
Removing the split has been central to the airport's long-term strategy to cope with an expected surge in demand over the next two decades, thereby reducing the need for urgent action on a second airport.
Virgin is urging the airport investigate building a high-frequency, light-rail link between what are now the domestic terminals - known as T2 and T3 - and the international terminal, or T1.
The airline believes that will be a considerably cheaper option than pursuing a major redevelopment of the terminals, which is expected to run into the billions of dollars.
Virgin chief executive John Borghetti said the existing plan would not solve, even after spending billions of dollars, the difficulty for passengers getting to the other side of the airport to catch connecting flights.
"The current facilities are Third World - and that means cab, bus or train," he said.
"We are still going to have separate terminals [if the airport proceeds with its plans], and irrespective of who is in them, we haven't solved the transfer issue between those two terminals."
He described the existing rail link between the international and domestic terminals as "difficult to find, difficult to get to and in a different league ... to lots of airports in Asia".
The "commuter train" did not run frequently enough to meet the needs of airline passengers, he said.
Airports around the world including those in Atlanta, Seoul, Madrid and Kuala Lumpur are well served with light-rail links connecting terminals every three to five minutes.
A spokeswoman for Sydney Airport said its plans to base domestic and international flights from the same terminals would allow for a "greater number of intra-precinct transfers".