Former federal Labor MP Steve Georganas faces a contest to regain preselection in the marginal seat of Hindmarsh.

Veteran member Delia Brennan will challenge Mr Georganas with the ballot to be held next month, though the Greek Australian candidate is widely expected to pull through.

Mr Georganas lost the seat at the 2013 federal election by a wafer-thin majority to Liberal Matt Williams.

Labor’s nominations for the seat of Sturt, which is currently held by federal government minister Christopher Pyne, have yet to be announced.

A final decision on Labor’s candidates will be made at a special conference on 27 August.

The Liberals hold six of the 11 seats in SA and anger towards the Coalition over the Future Submarimes contract has put three in particular – Hindmarsh, Sturt, and Boothby – at risk, while the seat of Mayo, held by Minister Jamie Briggs, is also considered up for grabs.

Senator Nick Xenophon has threatened to run candidates in all Liberal seats and direct preferences away from the Coalition to protest the broken promise on submarines.

Xenophon is expected to announce his candidates in every SA Lower House federal seat and on Senate tickets in October.