Canberra to spend $12.4b on Joint Strike Fighters

Australia will spend $12.4 billion to buy 58 F-35 Joint Strike Fighters as the Abbott Government throws its full support behind the high-tech warplane.

Tony Abbott will confirm today that the Government will go ahead with the purchase of the US-made plane, which should begin service in 2020.

The previous government had approved buying 14 F-35s but had stopped short of committing absolutely to the program amid long-running concerns about the stealth fighter's promised cost and performance.

The F-35 will replace Australia's ageing fleet of F/A-18A/B Classic Hornets, due to be withdrawn from service in 2022.

The Government is now committed to buying 72 F-35s, well short of the 100 stealth fighters originally planned when the Howard government first joined the JSF program.

But in making the announcement, the Prime Minister is expected to leave the door open to buy more F-35s.

"The fifth-generation F-35 is the most advanced fighter in production anywhere in the world and will make a vital contribution to our national security," Mr Abbott said.

"The F-35 will provide a major boost to the Australian Defence Force's intelligence, surveillance and reconnaissance capabilities."

Defence Minister David Johnston said the commitment would result in more than $1.5 billion in JSF-related production and support work taking place in Australia.

Manufactured by Lockheed Martin, the F-35 is the costliest program in the US military's budget.

The planes were billed as the smartest fighter jet in existence, built to sneak in under enemy radar and destroy targets from long distances.

But the F-35 has been beset by performance and software problems and cost overruns.

This year, a senior US Air Force commander appeared to suggest the aircraft was not built as an air superiority platform and could struggle in combat without protection from more manoeuvrable F-22 Raptor fighter jets.

Italy, Turkey and Canada have indicated they could pull out of the JSF program, greatly increasing the cost of each aircraft for Australia and the US.