The NSW electoral commissioner has rebuffed the Liberals' last-minute request to extend the nomination deadline for local elections after an extraordinary failure to submit forms on time.
The state electoral commission has confirmed it received a letter from party state president Don Harwin requesting the cut-off for the nomination period be extended by a week to August 21.
Acting NSW electoral commissioner Matthew Phillips considered the grounds for the request and on Saturday rejected an extension.
"He has determined not to extend the nomination period," a spokeswoman said.
AAP has contacted the NSW Liberals for comment.
The request was the latest step by the Liberals to recover after the party failed to submit up to 151 nomination forms before the deadline, leaving conservative voters with minimal options in some council elections.
The party was preparing to take court action if an extension was not granted, the Sydney Morning Herald reported.
State director Richard Shields was sacked on Thursday in response to the failure.
The party on Saturday preselected Monica Tudehope, a former staffer to Dominic Perrottet, to run in the former NSW premier's northwest Sydney seat of Epping.
Election analyst Ben Raue predicted the Liberals would lose "a whole bunch of seats and go a long way backward" in some councils.
The creator of the website TallyRoom has found 44 contests involving some 135 candidates who would be affected at the September 14 elections.
"There's going to be a lot more councils where there's just one party that runs the show, and generally that means a lot more decisions happen behind closed doors, in private, and I think you'll see a bunch more of that," Mr Raue told AAP.
"It's not very common in the big partisan urban councils that one party gets a majority."
Conservatives in some councils would likely receive an inflated vote count, he said.
"There's a few ex-Liberal members or 'rebel Liberals' in places like the Blue Mountains, Hornsby and Lane Cove who will probably just get a much bigger vote than they would have gotten," he said.
"But there are other councils where there's just no real good conservative options."
More than 150 candidate forms were never submitted, leaving 281 Liberals running across 30 council areas.
A statement from the Liberal NSW party issued on Friday evening declared the stuff-up was "simply not good enough" and confirmed it would reimburse endorsed candidates who had been affected.
"To prevent this from ever happening again, we are reviewing our process to thoroughly investigate what went wrong," it read.
"We are fully committed to implementing all necessary changes to strengthen our processes … while what happened is a setback, it will not define us."
