Labor leader Bill Shorten should watch his back now that factional powerbroker Stephen Conroy is bowing out of politics, a Liberal MP says.
Senator Conroy surprised colleagues including deputy leader Tanya Plibersek after quietly dropping his resignation notice to the Senate on Thursday night.
Liberal backbencher Tim Wilson reckons Mr Shorten should be concerned about the pending departure given Senator Conroy was always behind the Labor leader.
"So the question is who is going to have Bill Shorten's back?" he told Sky News on Saturday.
"It seems to me it'll be game on in Labor leadership if Bill Shorten doesn't get somebody to watch his back in the absence of Stephen Conroy."
But Labor backbencher Matt Keough says Mr Shorten is perfectly positioned in his job.
"Bill can still be secure and doesn't need to in any way fear from Stephen's departure."
Mr Shorten said he wouldn't criticise the Labor frontbencher, whose last day will be September 30, for choosing to put his family before politics.
"He steps down with the best wishes and the blessings of the Labor party," he told reporters in Washington.
Labor now has to decide who will replace the veteran Victorian senator and who'll take up his posts as deputy leader of the opposition in the senate, shadow special minister of state and opposition sports spokesman.
Mr Shorten has ruled out a reshuffle, saying it would be a normal process of change.
"There's no great black magic about how we do it - we've got rules and processes."
Victorian Labor's 100-member public office selection committee will meet in coming weeks to determine a replacement for the party powerbroker.
The committee is controlled by a factional alliance led by Mr Shorten, Senator Conroy and the Left's Kim Carr.
However, the next person on Labor's voting ticket at the July 2 election was former mayor of suburban Maningham Jennifer Yang, who is factionally unaligned.
Meanwhile, Mr Shorten revealed Senator Conroy gave his resignation notice to him via text message.
The Labor leader was in Montreal attending a conference when he received the message but was unable to contact Senator Conroy before he tabled his statement.
Independent senator Derryn Hinch wasn't buying Mr Shorten's explanation, calling it "bulldust".
"Cites time difference for failing to talk to Conroy. At 9p.m. when he quietly quit it was 7a.m. in Montreal," he tweeted.
