The Albanese government is poised to expel the Russian ambassador over the feared execution of Melbourne soldier Oscar Jenkins in Ukraine, whose possible death has also shut down prospects of a prisoner swap for two alleged Russian spies accused of stealing military secrets.

A furious Prime Minister Anthony Albanese vowed to take the “strongest possible action” against Russia if Mr Jenkins had been killed, as bilateral relations between Canberra and Moscow plunged to their lowest point since the 2014 downing of Malaysian Airlines Flight MH17 over Ukraine, when 38 Australians were among those killed.