German shipbuilders jostling to win the right to build Australia’s next fleet of submarines are convinced they will remain in the race for the project when the Government announces a selection process “within days”.

ThyssenKrupp Marine Systems has offered an enlarged version of an existing conventional submarine on a fixed price contract it claims could be capped at $20 billion for 12 boats.

Sources close to the bid team have acknowledged that Japan’s Soryu class submarine probably remains in favour with the Australian Government, but added they “did not believe it’s cut and dried with the Japanese solution” and the Government was “going to too much trouble” to keep them engaged.

The ABC has previously reported the Government was due to make an announcement on the submarine selection process earlier this week but delayed it after the Martin Place siege in Sydney.

The replacement of the Collins class submarine from around 2026 will be Australia’s biggest ever defence project, with some estimates ranging over $60 billion.

The ThyssenKrupp bid team has pressed its case at “the highest level of government” for a “competitive process” to select the bidder.

The company anticipates that it, the Japanese, and French shipbuilder DCNS would likely be included.