Defence experts warn that plans to spend more than $300 million of taxpayers’ money on a factory capable of churning out 4000 missiles a year risks coming two years too late for a potential showdown with China over Taiwan.

Defence Industry Minister Pat Conroy defended the delay as he unveiled the centrepiece of the government’s pledge to mass-produce missiles locally as part of a drive to make Australia more self-sufficient and boost stockpiles of munitions, while also giving the US and other allies an alternate source of supply.