The Greens have chosen a female native title lawyer to contest Tanya Plibersek's federal electorate of Sydney as the party prepares to target what it believes are five winnable lower house seats in NSW and Victoria this year.

Sylvie Ellsmore, a lawyer and Marrickville councillor, won preselection for the Greens on Thursday night.

Tanya Plibersek's stance on a binding vote for Labor MPs on same-sex marriage did her untold damage. Credit:Andrew Meares

Ms Ellsmore is a former NSW Greens campaign co-ordinator who worked for a decade as an Indigenous rights advocate.

She prevailed over Bruce Knobloch who had originally set his sights on contesting Anthony Albanese's seat of Grayndler before the Greens chose former fire brigade union boss Jim Casey as its candidate.