One of the largest shipping companies operating in Australia has been accused of failing to comply with legal obligations to prioritise local workers amid suspicions it wants to fill up to three dozen positions with foreign workers under the 457 visa program.

Canadian-owned CSL has recently taken applications for various positions - including marine engineers, fitters and mechanics - on its Australian-flagged fleet of vessels operating along the coastline.

According to the Australian Institute of Marine and Power Engineers, more than 60 qualified Australians have applied for the jobs. The union is concerned CSL is not meeting its local labour market testing requirements and intends to seek 457 visas for cheaper foreign workers.

The matter has revived Labor calls for further tightening of the 457 program, with Victorian MP Julian Hill urging Immigration Minister Peter Dutton to "back fairness in the system" by committing to reject any relevant foreign worker visa nominations from CSL.