The Liberal candidate vying to be the next state member for North Shore has apologised for wrongly claiming to have lived in the electorate for a decade.

Felicity Wilson, the favourite to win Saturday's by-election for the seat, said it was an "unintentional error" when she told party members she moved to the North Shore electorate in 2005.

During the Liberal Party preselection battle that led to her nomination, Ms Wilson said she had lived in Waverton, Wollstonecraft and Neutral Bay "for 10 years".

This assertion was repeated in a statutory declaration as part of her nomination form lodged with the party.

But after journalists started questioning the claim, Ms Wilson admitted it was wrong.

"At the time of writing my nomination form, I believed it to be true that I had lived in the North Shore electorate for 10 years," Ms Wilson said in a statement.

"However, upon further reflection I have since realised that figure is not accurate.

"Rather, I have lived in and around Sydney's North Shore region for the best part of 10 years.

"I sincerely apologise for my unintentional error."

Felicity Wilson claims she voted for John Howard in 2001. ( Facebook: Felicity Wilson )

Ms Wilson has told the ABC she made another "unintentional error" in a Facebook post about former prime minister John Howard.

In the post, which included a photo of her and Mr Howard, she claimed the first vote she cast in an election was for Mr Howard.

"The first vote I ever cast in an election was for John Howard in 2001 when I was a student living in Bennelong. He told me this morning he'd return the favour," the post read.

However, electoral roll records show Ms Wilson was actually registered at an address in Marrickville, which is in the seat of Grayndler, the other side of the Harbour from Bennelong.

She has responded by saying while she voted for the Howard government in 2001, it was not until 2004 that she voted for Mr Howard personally while she was living in his electorate.

Records show that in June 2004 Ms Wilson was living at Brighton Le Sands in the seat of Barton, and by February 2005 she was enrolled in Bennelong.

The election was held in October of 2004.

In her statement, Ms Wilson said she took the opportunity to represent the area seriously and would be submitting a revised statutory declaration to the Liberal Party as soon as possible.

'It's not that she's an outsider, it's that she fibbed'

NSW Liberal Party state director Chris Stone said he had spoken to Ms Wilson about the matter.

"I accept her explanation and statement that she made an unintentional error on her nomination form and in a social media post," Mr Stone said.

However State Opposition Leader Luke Foley said voters in the seat would not be impressed.

"Ms Wilson's got as much connection with the seat of North Shore as I do and I'm the member for Auburn," he said.

"She needs to explain why she's padded and embellished her connections with the seat she's seeking to win on Saturday.

"The real crime here isn't that she's an outsider, it's that she's fibbed."

Liberals are expected to retain the seat of North Shore this weekend, which was left vacant when former health minister Jillian Skinner quit politics.

However there could be big swings as the controversial forced council amalgamations policy is very unpopular in the North Shore.