Sad, pathetic, one of the great Labor rats of history - and that's just what Mark Latham's former friends say about him.
The former federal Labor leader on Monday released a One Nation ad smearing Opposition Leader Bill Shorten as a liar, sparking a furious reaction from his former party.
"Mark Latham has become a pretty sad and pathetic figure," Labor frontbencher Jim Chalmers told Sky News on Tuesday.
Shadow treasurer Chris Bowen said Mr Latham fell out with everyone he ever worked with.
"He will go down as one of the great Labor rats of history," Mr Bowen told reporters.
Mr Latham led Labor to a crushing defeat at the 2004 federal election, giving John Howard's coalition control of both houses of parliament.
"If Mark Latham does to Pauline Hanson's vote what he did to Labor's vote, I'm not at all worried," Labor deputy leader Tanya Plibersek told reporters.
Mr Shorten brushed off the attack as "a sideshow".
"Mark Latham used to be someone, he's not anymore," he told reporters in Tasmania ahead of the by-election in Braddon.
Foreign Affairs Minister Julie Bishop pointed out the irony of a man Labor previously proposed as an alternative prime minister calling Mr Shorten a liar.
"For the first time in a long time, I agree with Mark Latham," she told reporters in Canberra.
On Monday night Mr Latham would not rule out running for One Nation at the next federal election.
But Liberal Democratic senator David Leyonhjelm said Mr Latham was a paid-up member of his party, although he hadn't directly communicated with him since May.
"He's still not sure that he wants to be a politician again. So that's the threshold test," Senator Leyonhjelm told AAP.
The former Labor leader has been drawing a hefty parliamentary pension and working as a controversial commentator since leaving Canberra.
Former ALP powerbroker Graham Richardson confronted Mr Latham on Sky News on Monday night, calling him a "king rat".
"It's a tragedy and it's sad, Mark," Mr Richardson said.
Senator Hanson said it would be fantastic to have Mr Latham beside her in parliament.
"I think someone of Mark's knowledge, experience and willingness to speak against political correctness is much needed," Senator Hanson said on Monday.
In the robocall, Mr Latham blamed Mr Shorten for causing the by-election in the Labor-held seat of Longman because of his mishandling of the dual-citizenship issue that engulfed federal parliament last year.
"I've had personal experience with Bill Shorten's dishonesty. He just lies and lies and lies," Mr Latham said in the call.