Devil's Corner Vineyard, which is owned by Tamar Ridge, has proposed to build an observation platform atop Cherry Tree Hill, on its private property.

The 12-metre-high lookout would be for the benefit of customers.

The proposal was heard at a Glamorgan Spring Bay Council meeting in March and was unanimously approved by councillors.

Bicheno resident Janet Lane has joined the public outcry against the development.

She has called the plan shameful and believes the new lookout will spell the end for the nearby Great Oyster Bay lookout.

"While one understands them trying to bring customers to their cellar door, the upshot of all this is terribly sad for the whole East Coast and all our visitors, family and tourists," she said.

"It means the public viewing park currently on Cherry Tree Hill - an iconic stop for everyone - will be shut down. People will have to go to a business down a side road instead."

Glamorgan Spring Bay mayor Michael Kent acknowledged that the Great Oyster Bay lookout could be scrapped.

"It's unsure whether there will be two, or one lookout in future," Cr Kent said.

"From what I have heard there are cars parked around the wrong way on the opposite side of the road at the Great Oyster Bay lookout. It's dangerous, but I do understand that there hasn't been an accident there before."

Cr Kent said the Department of Main Roads would determine whether the Great Oyster Bay lookout was a roadside hazard.

Tamar Ridge general manager Will Adkins said he did not want the Devil's Corner development to rub people the wrong way.

"We don't want people to think we're trying to close the [Great Oyster Bay] lookout down," he said.

"Our plan is to add to the cellar door."