Mrs Coker will stand as the Labor candidate in the seat held by the Coalition with an ultra-safe 13 per cent margin after former candidate Joe Brown stepped down from the position three months ago.

Labor assistant state secretary Kosmos Samaras said Mrs Coker was a strong candidate and showed the party was intent on mounting a serious challenge. “We endeavour to preselect the best possible candidate for each seat,” Mr Samaras told AAP.

“Unfortunately, sometimes for personal reasons, some candidates can’t continue on and that was the case with the previous candidate (Mr Brown) preselected for the seat.”

Mrs Coker said she has lived in the seat for 27 years and had a background in local government and as a small-business owner and teacher.

“It is only Labor that will build a new secondary school for the people living in the rapidly growing town of Bannockburn,” Mrs Coker said in a statement. “I believe it is time for the people of Polwarth to make their voices heard, and send a clear message to the Napthine government that while Polwarth is a safe Liberal seat, they still expect action on the issues that are affecting their lives.”