The admission by Mr Nutt, who was conducting a pre-election candidates forum with Premier Mike Baird in Sydney on Sunday, is the closest yet to an admission by the Liberal Party machine that the unpopularity of Prime Minister Tony Abbott threatens to directly impact on the state campaign.

According to sources inside the forum, candidates were instructed not to comment on the leadership of Mr Abbott to journalists and to confine all comments during their campaigning to state issues.

But in private groups, candidates raised fears that seats that should be winnable could be out of reach if Monday's leadership spill motion is defeated and Mr Abbott holds on to power, as his supporters suggest will be the case.

Fairfax Media has been told that some voters have warned they will register a protest vote against the Liberal Party if there is no leadership change.

Candidates contesting seats in western Sydney, the south coast of NSW and the Sutherland Shire reported negative feedback on the streets.

Fairfax revealed two days before the wipe-out of the Newman government in Queensland that Liberal head office was worried for Liberal-held metropolitan seats like Coogee, Strathfield, Campbelltown, Parramatta, Rockdale and Oatley.

According to sources, internal party polling at a state level had identified a negative "Abbott factor" that could play a part in the campaign.

A state government MP said he was not aware of a single colleague who had invited Mr Abbott or Treasurer Joe Hockey to any campaign events.

Some spooked sitting Liberals are even worried that they could be forced into minority government if the worst case scenario happens on polling day, Saturday, March 28.

But Mr Baird, whose Manly electorate sits within Mr Abbott's Warringah electorate, has backed his "mate" to survive the spill motion and has said he will feature at the Liberal campaign launch in March.

Mr Nutt, worked as an adviser in the office of John Howard and sat on the Abbott government's "star chamber" staff selection panel with the Prime Minister's chief of staff, Peta Credlin, before being drafted to run the NSW branch. Contacted by Fairfax Media, he said he would not comment on statements made at a private forum.

Attendees at the forum, to mark 50 days until NSW goes to the poll, included state ministers Jillian Skinner and Stuart Ayres.

A government source who attended said some of the fears of the candidates were overblown because the downfall of the Newman government could not be compared to the way the Baird government has tracked since the former premier Barry O'Farrell resigned.

"Newman was a brand killer but Mike is a different person. He has a narrative and people like him. He actually has substance."