Don Farrell's potential return to the Senate threatens one of Labor's leading female senators just after the party implemented reform to boost the number of women elected to Parliament.

The ABC reported this morning that the former secretary of the shoppies' union would be putting his hand up for preselection in South Australia for Labor at the upcoming election. Farrell lost his Senate seat to Family First Senator Bob Day after agreeing to relinquish the top ticket spot in the 2013 election to Labor's leader in the Senate, Penny Wong. After a failed bid to enter South Australian Parliament, Farrell, known in SA as The Godfather, would likely get the second spot on Labor's ticket if he wins preselection.