Madeleine Ogilvie will sit as independent when she takes her seat in Parliament today.
The last independent to sit in the House of Assembly was former federal Liberal MP, the late Bruce Goodluck in 1996.
Ms Ogilvie has shunned media since her election on a count back to replace Labor member for Clark Scott Bacon who retired. She has refused to respond to media calls and inquiries.
However, she took to Facebook to say she was concerned about stability and has spoken with a public relations firm to announce her intentions to sit as an independent.
Labor leader Rebecca White this morning said she "respected" Ms Ogilvie's decision to sit as an independent.
"Madeleine and I have had constructive discussions in recent weeks about her future if she was successful in the recount," Ms White said.
"I always said that it was for Madeleine to decide whether to re-join the Labor Party.
"I respect Madeleine's decision to sit as an independent and I look forward to working with her in the Parliament."
Ms Ogilvie stood for Labor at the 2018 state election but lost her seat to popular newcomer Ella Haddad.
She won the recount by just 200 votes from former ABC presenter Tim Cox - one of the closest recounts for years.