Mr Rudd dramatically announced from overseas on Wednesday evening that he was quitting the frontbench.
He accused Ms Gillard of deserting him in the face of continual attacks on his integrity by a "number of faceless men" and frontbencher Simon Crean.
The prime minister is expected to announce on Thursday morning that there will be a leadership spill on Monday.
Mr Rudd's numbers man Alan Griffin says the former PM will have the opportunity to put his case for a return to the top job when he arrives home from the United States on Friday.
But Mr Griffin says Mr Rudd won't quit politics if he loses a leadership ballot.
"I'm sure Kevin will stay in the parliament - there's absolutely no doubt about that," Mr Griffin told ABC radio on Thursday.
A small number of fellow backbenchers supported Mr Rudd publicly on Thursday morning ahead of Ms Gillard's press conference in Adelaide.
But a raft of senior ministers took to TV and radio stations to continue to attack Mr Rudd's reputation, again led by Mr Crean.
"He (Mr Rudd) is going to get and should get an important message on Monday and that is the party wants discipline," the regional Australia minister told ABC Radio.
"The party wants the phoney war to stop. We now know that the phoney war has been exposed. It's going to be brought to a conclusion. That's where the line should be drawn."
Deputy Prime Minister Wayne Swan continued his criticism of Mr Rudd's character, describing him as a "deeply flawed" man whose weaknesses were not seen in public.
Following a scathing statement on Wednesday night - when he maintained the former foreign minister had sought to tear down Labor's 2010 election campaign - Mr Swan was on the front foot again on Thursday.
"I've worked with Prime Minister Rudd, I've worked with Prime Minister Gillard," he told ABC Radio.
"The truth is, the Prime Minister Rudd is deeply flawed.
"He does have some very significant achievements ... but he (also) has great weaknesses which to date, have not necessarily been seen in public."
But there was some support.
Labor backbencher Janelle Saffin said the removal of Kevin Rudd as prime minister was a breach of trust with the Australian people and Labor had been paying the price ever since.
Ms Saffin, who represents the NSW north coast seat of Page, said she would back Mr Rudd in a leadership ballot.
"Yes I will because that's what the people here in Page and across Australian want," she told ABC radio.
"They elected him in 2007. In 2010 when he was removed, and not by them, they see that as wrong and it was wrong and we have been paying the price ever since."
Senator Doug Cameron also reiterated his support for Mr Rudd.
