High-flying businessman John Wagner says he could build Sydney's second international airport for much less than its touted $6 billion pricetag.
Mr Wagner and his brothers were behind the Brisbane West Wellcamp Airport near Toowoomba that opened late 2014, the first major airport to be built from scratch in Australia since Melbourne's Tullamarine in 1970.
The airport, with its 2.87km runway capable of handling aircraft as big as a Boeing 747, took 19 months and 10 days to build, and cost $200 million.
Mr Wagner says he could build Sydney's Badgerys Creek airport in three years.
"We just can't see that it would cost that much, and the high-level work that we have internally here would indicate that it shouldn't cost that much," Mr Wagner told ABC on Tuesday.
The federal government last week committed to building the Badgerys Creek airport after Sydney Airport Corporation, which operates the existing Mascot airport, walked away, citing "considerable" risks.
"It is a vitally important project for western Sydney, for Sydney and the nation," Prime Minister Malcolm Turnbull said in a statement.
Earthworks on Sydney's second international airport are due to start next year and is likely to be operational by late-2026.
Last year Infrastructure Australia costed the first stage of the Badgerys Creek airport at $5 billion.
Further details are to be outlined in Tuesday's federal budget.
