Bournemouth council has raised fears that a £3bn offshore wind farm could deter visitors from the south coast.
Navitus Bay plans to build up to 218 turbines off Dorset and Hampshire, 12.2 miles (175 sq km) from Bournemouth.
New research suggests that may put off some tourists from visiting the Dorset coast. Borough councillor Mike Greene said that could “devastate” tourism.
Navitus Bay has said it believes there will only be a small negative impact which is “not significant”.
The results are part of an assessment done for the developers in which 302 businesses and 2,027 visitors to the south coast were interviewed.
Bournemouth borough councillor Mike Greene said: “For 14% of visitors, for one in seven, they state that the presence of the project would spoil the views and prevent them from returning.
“When you go forward to the construction period, which we know is going to be around four-ish years, that goes up to one in three. One in three of Bournemouth’s visitors say they would not come purely because of the wind farm.
He added: “We are talking about a tourism industry in Bournemouth that was worth £500m a year. This will absolutely devastate it.”
Navitus Bay project director Mike Unsworth said: “We have done two years of detailed, extensive surveys and the results in my mind are positive.
“Eighty-six per cent of the visitors surveyed don’t believe the wind farm would have any impact on them visiting the area, and of the tourist businesses we surveyed 92% were very positive and encouraging about their future which is fantastic for the area and 72% of those businesses didn’t think that the wind farm would have any impact.”
He added: “The evidence clearly does not show that tourism is impacted significantly or negatively from these offshore wind farm developments.”
Mr Unsworth said the project would bring about 2,000 jobs to the region and 200 long-term jobs in operations and maintenance.
Developers claim the wind farm will provide enough renewable energy to power up to 790,000 homes.