Japan Inc will back the development of one of the world’s biggest nickel deposits in Western Australia in a move that casts further doubt on whether the Albanese government will bail out BHP and its struggling operations.

Sumitomo and Mitsubishi have agreed to back Ardea Resources and its $3.1 billion nickel laterite and cobalt project, about 80 kilometres from Kalgoorlie and BHP’s ageing nickel smelter.