SA Liberals tour Japanese shipyards

South Australian opposition leader Steven Marshall will tour Japanese shipyards as the country prepares its final bid to build Australia's next fleet of submarines.

Tuesday's visit follows Mr Marshall's tour of French and German shipyards as he pushes to ensure submarines are built at ASC in Adelaide.

Japan, which has said it would build the submarines in Australia, is bidding along with Germany and France in a competitive tender process, with submissions due at the end of November.