Adjust Professor Brett Billington, who contributed to Defence's recent space domain review, was critical of announcements that "simply failed to achieve the numbers of qualified [science, technology, engineering, and mathematics] graduates and technicians that Australia needs".

Governments treated these workforces like a replenishing Magic Pudding created by children's author Norman Lindsay, Dr Billington said.

"Our approach is a fantasy," he told Defence leaders at its recent air and space power conference. "Our leaders make announcements that imply or assume the presence of a STEM workforce capable of doing all that is asked of it - or they say nothing about it, and just assume it's going to happen."

Recent government decisions including establishing a future nuclear-powered submarine fleet, a sovereign guided missile enterprise, a Space Command as a precursor to a Space Force, while investing in sophisticated cybersecurity, electronic warfare, and command control communication capabilities.

"The uniform, civilian and contract workforce needed to meet these demands simply does not exist," Dr Billington said, adding that companies within the defence and manufacturing sectors were already poaching workers from each other, within and between sectors.

Four defence industry small business founders who spoke to The Canberra Times said poaching by international firms was making it difficult for a sovereign industry to grow in Australia.

Defence Minister Peter Dutton said the Australian Signals Directorate will be able to attract and retain an additional 1900 workers.

"It's exciting - we had something like 9000 applications last year for jobs here," the minister told reporters on Thursday during a media conference on ASD's REDSPICE funding.

Eventually these recruits would leave, and the skillset they've built would be an asset to them and the organisations they move to, he said.

Defence's information warfare division is also attempting to recruit more cyber specialists early in their careers by offering an ADF Cyber Gap Year. The division's head, Major General Susan Coyle, told a recent industry seminar hosted by the professional association ACS that skilled people were the single most-important input to Defence's cyber capabilities.

"We don't have to retain everybody in uniform with inside the Department of Defence - I'm a realist, but what we do need to do is make sure that this talent stays within the national security architecture."

Defence must also part ways with its talent on good terms, she said, so they can return when Defence needs them.

The government also wants Australia's space sector to grow, by up to 20,000 new jobs by 2030. Dr Billington called this "Magic Pudding thinking in overdrive" based on an Academy of Science report to the Chief Scientist noting universities would need to produce 300 new scientists, 900 engineers and 800 non-STEM graduates each year over the decade just to service the space sector.

The government's stream of announcements would mean nothing without a deliberate planning process for a STEM worker pipeline, said Dr Billington. He urged the government to invest in sending more Australians to overseas universities to experience and participate in research at levels Australia cannot match.

It also needed to invest in primary school teachers to teach mathematics confidently and enthusiastically, he said.

"STEM competence needs to be part of life, a common experience accessible to and accessed by all, and that starts with the students in their earliest years of school, who in turn, will teach their parents and their carers when they get home.

"Magic Pudding thinking has no part in developing the sustainable STEM pipeline of the citizens on which the security and future of our nation depends."