THE firm behind a proposed passenger-carrying balloon for Southampton has urged aviation authorities to ease "unreal" rules about the height it can fly.

Southampton Airport owners BAA blocked plans to float the tethered helium-filled balloon up to 400ft above Andrews Park insisting it would compromise the safety of aircraft flying as low as 5,000ft over the city centre.

However, it has emerged that BAA made no objection to a 276ft high hotel that will be built just yards away in East Park Terrace.

Alastair Gunning, director of Lindstrand Aerial Platforms, said he still hoped to persuade the Civil Aviation Authority to give him clearance to fly near to the originally proposed height to provide passengers with 25-mile panoramic views. A similar attraction in Bournemouth flies up to 500ft - although is not on approach path for Bournemouth Airport.

Mr Gunning said: "We are in a somewhat grey area. We are not a building; we are an aircraft and will have markings at night.

"If a plane is going to be flying as low as 400ft it's probably going to hit a building. The whole thing is thoroughly unreal."

Mr Gunning said plans to launch the balloon this summer had already been derailed. He said he wanted to anchor the balloon in Andrews Park because it was well used and would provide the best views of the city.

Councillors and tourism chiefs seeking a wow factor for the city have backed the balloon, dubbed the Southampton Eye.

Tory council leaders offered to help find another location if the safety row cannot be resolved.

Councillor Phil Williams, the Cabinet member responsible for parks, said: "We would be happy to help them look at other possible locations. It's something that is worth exploring."

Cllr Williams added that Mayflower Park might be an option.

John Hannides, Cabinet member for leisure and culture, said the balloon was exactly the kind of idea the Tories were keen to encourage.

He added: "However we must be mindful of the safety issues that are relevant to any proposal that comes forward."

BAA said the hotel would be a "substantially lower height" than the balloon and met "strict safety criteria laid down by the Civil Aviation Authority". However, a spokesman could not confirm the exact safe height for the proposed site.

A CAA spokesman said it was for airports to interpret its guidelines locally.