Barry Howlett, executive director of the Australian Deer Association Credit:Paul Jeffers

Victoria's feral deer population estimate has soared past more than one million, triggering government plans to unlock more of the Alpine National Park to hunters of a species described as "giant-hoofed cane toads".

Deer numbers have exploded in Victoria since the 2009 Black Saturday bushfires and the animals are increasingly invading Melbourne’s suburban fringe, causing car crashes and environmental damage in national parks including the Grampians and Wilsons Promontory.

Four outer eastern suburbs councils wrote to Premier Daniel Andrews on Friday, pleading for government help and cash to tackle a problem they argued was hurting agricultural businesses, reducing biodiversity and putting lives at risk.

The letter, from the Manningham Council and Yarra Ranges, Cardinia and Nillumbik shires, says deer should be officially classified as a pest species, a move the Labor government has resisted.