Malcolm Turnbull's NSW Liberal power base risks plunging into "meltdown" over internal reforms, Tony Abbott has warned.
In July, the former prime minister led the charge for changes to Liberal Party rules in a bid to water down the power of the dominant moderate faction.
He declared the passing of the resolution - which would give grassroots members a greater say in selecting candidates and filling official positions - as a "great day" for the party and good for the coalition government and the country.
The reforms still need to be endorsed by the party's state council which is due to meet on December 9.
But there are fears state election candidate preselections could be called early, before the reforms are approved, meaning the candidates would be selected on the old rules.
Mr Abbott warns the Liberal Party would "have an absolute meltdown" if reforms are shelved.
"Setting up the convention in an effort to have the whole thing go away, failing in that attempt and then attempting to sabotage the result of the convention - I think that would spell very, very dark days indeed for the NSW party," he told Ray Hadley on 2GB radio on Monday.
"I don't think the premier wants that, I don't think the prime minister wants that."
Mr Abbott endorsed one of his fellow reformers, former Major General Jim Molan, to take over the state party presidency.
He also revisited the decision to push Mr Molan down the NSW Senate ticket for 2016 in favour of the Nationals' Fiona Nash, only to see her disqualified by the High Court recently.
"It was embarrassing, frankly, that Jim Molan was not given a winnable position on the Senate ticket," Mr Abbott said.
Mr Molan is also concerned about the reforms being dumped.
"I am deeply suspicious," he said in an email to party reform supporters.
"I caution outgoing state executive against this move. It is hard to imagine a more clumsy attempt to retain centralised control and defy what the membership has clearly said they want - namely democratic plebiscites to elect our candidates."
