More than 300 doctors and other medical professionals have signed an open letter demanding the state government develop a plan to retire the Latrobe Valley's brown coal power plants because of the health damage they cause in the local community.

The letter, organised by the group Doctors for the Environment Australia, argues a transition away from brown coal-fired power – responsible for 85 per cent of Victoria's electricity generation – is necessary because its pollution is responsible for local disease, and even death, and poses a broader health threat through a contribution to climate change.

A giant dredging machine at work in the brown coal mine at Loy Yang in the Latrobe Valley. Credit:John Woudstra

The letter is an attempt to heap pressure on the Andrews government to include measures to start retiring the valley's four brown coal plants as part of its promised state renewable energy plan, which is expected to be released in coming weeks.

Dr John Iser, the Victorian chair of Doctors for the Environment and a retired gastroenterologist, said the state government had carried out "commendable" work to inform its clean-energy strategy, but it was still "paper planning" and the doctors group was "getting fed up with the lack of action".