Baggage handlers, caterers, engineers and maintenance staff will undergo random testing for explosives in a new security crackdown, but Nick Xenophon says the changes are a “joke” that do not go far enough.

The federal government announced the new measures on Sunday, just months after an alleged plot to smuggle an explosive on to an international flight from Sydney Airport was foiled.

The transport minister, Darren Chester, said the new checks strengthen existing controls by ensuring airport staff are authorised and appropriately trained before entering secure areas. They may also be checked while working.

“Airport workers, together with their vehicles and belongings, will be randomly selected for explosive trace detection testing and other screening when entering or working in secure airside areas at major airports,” Chester said on Sunday. “Other measures being introduced include stronger access controls and additional security awareness training for aviation workers.”

Pilots, terrorism experts and the Transport Workers Union have lobbied for strengthened screening of workers including casual staff and sub-contractors.

The move to beef up security comes after authorities claimed to have foiled an alleged terrorist plot in which a military grade explosive was stashed inside luggage to be put on a 15 July flight from Sydney to Abu Dhabi.

Chester said the new rules would be implemented progressively to provide flexibility for airports.

But Xenophon said the changes were a “joke” that do not go far enough. The senator wants a US-style agency to be responsible for airport security and vowed to pursue the matter during Senate estimates this week.

“Australian aircraft passengers deserve the world’s best practice when it comes to security but the government’s measures fall well short of it,” Xenophon said. “In countries like the US, all airport staff are required to be screened. Our government’s approach to random inspections is a joke.

“Systems of checking can be easily bypassed. People with evil intent can be tipped off by mates and avoid random screening.”

The prime minister, Malcolm Turnbull, announced earlier in the month that facial-recognition technology would be enhanced up as a counter-terrorism measure.

State governments agreed with the changes, along with new commonwealth offences for terrorism hoaxes and the possession of the instructional terrorist material.