Woodside manager Tania Lawrence is the party's second candidate in as many weeks for the June 23 by-election, which was triggered by the resignation of disgraced Labor-turned-independent MP Barry Urban, who lied about his education and police service record.

Premier Mark McGowan said vetting for Ms Lawrence had been "extensive" given her predecessor Colleen Yates quit the race last week - just days after being endorsed - over exaggerations in her online resume.

"Obviously in elections going forward in Western Australia, clearly there will be a lot more scrutiny of individual candidates," Mr McGowan told reporters on Thursday.

"There's been extensive examination and I'm totally confident in Tania."

Ms Lawrence, who has also worked in the public sector including in counter-terrorism, said she produced physical evidence of her study history and was asked if the Urban and Yates dramas had put her off nominating.

"Obviously there are significant and concerning issues in relation to Barry Urban and more recently Colleen Yates, and I understand that, I recognise that but I'm putting that past behind me," she said.

"I'm here now and do believe I can be that strong working voice for the electorate.

"I have been as heavily scrutinised as I have in the past when I filled out national security clearances for government."

Asked if she was a "captain's pick", the premier said he'd been a strong advocate for her.

Opposition spokesman Tony Krsticevic said he had no faith Labor had got things right the third time around.

Mr Krsticevic also criticised the ALP's policy of having candidates delete their social media accounts once endorsed.

"If they have nothing to hide, why would they be doing that as a matter of course?" he said.

Australian Associated Press