Up to 161 workers fear the loss of their jobs with the future of bus manufacturing in NSW at risk after a company in Western Sydney went into administration.
Custom Bus, which manufactures buses in Villawood, on Friday said it had gone into administration but would not confirm how many of its workers were being made redundant.
"We are still trading," a company spokeswoman said.
The Australian Manufacturing Workers' Union said it expected up to 161 employees could lose their jobs if the company is liquidated.
It said a skeleton crew of 56 staff were working on finalising a current order.
AMWU secretary Steve Murphy said the threatened closure of the factory follows the NSW government's decision to contract companies in other states and overseas to manufacture new buses.
"The NSW government could have had these buses made right here in Sydney but instead they sent the work to Malaysia," Mr Murphy said.
"These job losses lay squarely at the feet of the Transport Minister Andrew Constance.
"Andrew Constance can't run the rail system, he bungled the naming of a ferry and now he has made an appalling decision to send a bus contract overseas that is costing Australian workers their jobs."
Mr Constance declined to respond to Fairfax Media's request for comment.
A spokesman for Transport for NSW said since January 2015, Custom had been involved in the production of 189 new buses for Transport for NSW contracted operators. A further 25 buses were in production with Custom when they entered administration. The spokesman said Bustech and MAN were the only double-deck buses that met existing vehicle registration requirements and neither were based in NSW.
The spokesman said applicants were asked to demonstrate how they would support local industries on large projects as part of the 2015 tender process for bus procurement.
"Several manufacturers on our bus procurement panel sub-contract to Custom to build the bodies of their buses," the spokesman said.