Steve McGhie, the retired state secretary of Ambulance Employees Australia Victoria, told AAP he decided to throw his hat into the ring after the seat became vacant.

"I am nominating and will see how we go," Mr McGhie said.

"It has not been finalised. It should be finalised at some time (on Friday). I am not aware whether anyone else has nominated."

He said he'd never planned it but when the seat became vacant, he saw an opportunity.

Premier Daniel Andrews' office has been contacted for comment about Mr McGhie.

Mr Andrews had promised voters an "outstanding candidate" after Justin Mammarella withdrew, citing family reasons, from the safe seat on Thursday.

It's not the first time the seat has been pulled into the spotlight after retiring member Don Nardella, a Labor MP turned independent, was forced to resign as deputy speaker after claiming a second residence allowance.

Mr Andrews on Friday is expected to reveal his plan to make retailers sell cheaper default power deals while Opposition leader Matthew Guy is to announce a discounted energy proposal for nearly one million Victorians, News Corp Australia reports.

While Labor firms up a Melton candidate, the Victorian Greens leader Samantha Ratnam will unleash an election promise to tax developers who hang onto land to make a quick buck.

Ms Ratnam will call for a windfall rezoning tax - which would be levied at 75 per cent of the difference between the assessed land value before and after rezoning - at the Urban Development Institute of Australia Summit in Melbourne on Friday.

The Greens' plan also will give developers buying land two years to "use or lose it".

Australian Associated Press