Instead, the paper states that to replace the newer current squadron of Super Hornet aircraft from about 2030, alternatives will be "considered … in light of developments in technology and the strategic environment and will be informed by our experience in operating the Joint Strike Fighters".

A US Predator drone. Credit:AP

Asked during a briefing on the white paper what Defence was planning, Air Chief Marshal Mark Binskin – himself a fighter pilot – said it was keeping an "open mind", given the rapid improvements in armed drones or "unmanned combat aerial vehicles".

"We're going to be open-minded because if you go ... say 10 years between now and when we consider [the next planes] ... you are starting to see the evolution of the UCAVs, unmanned combat aerial vehicles. So I think we need to keep a bit of an open mind … We shouldn't just lock in and say 'That's the way it's going to be for 50 or 100 years'."

The JSF, which is highly advanced but has been beset by delays and niggling flaws, is known as a "fifth-generation" aircraft, relying heavily on stealth and its ability to see the enemy at great distances so that it never has to get into a direct fight.