Labor's party president has praised union boss Paul Howes, who is tipped to fill former foreign minister Bob Carr's seat in the Senate.
Senator Carr is on his way back to Australia after representing the nation at the Group of 20 leaders' summit in Russia.
There is now speculation the former NSW premier, who was re-elected to the Senate at the weekend, will announce his resignation in coming weeks.
Mr Howes is national secretary of the Australian Workers Union and a member of Labor's national executive.
ALP president Jenny McAllister says it's a matter for the party's NSW branch.
"Paul is obviously a fine contributor and he represents the labour movement very well at the moment in his current position and he would be a great representative for the labour movement in another role," Ms McAllister told Sky News on Monday.
"But I'm sure there will be plenty of people putting themselves forward should a vacancy come about."
Comment is being sought from Mr Howes and the NSW ALP.
