IT is a world-leading trade show which keeps Southampton at the heart of the maritime industry.

Many millions are ploughed into the city economy when marine bigwigs arrive for the annual Seawork exhibition.

But the event could quit Southampton, taking its millions of pounds of investment with it, if campaigners win their fight to move it off a much-loved green space.

The city council is braced for a legal challenge from community groups upset that Mayflower Park was closed for four weeks in June.

They say they have been denied the area’s main open space for huge chunks of summer, with Southampton International Boat Show also taking over in September.

The man behind Seawork – which is worth an estimated £100m a year to the city – has raised the prospect of setting sail for good if it is forced to leave Mayflower Park.

“For Seawork to stay in Southampton, I’m not sure there’s an alternative venue,” said Andrew Webster, chief executive of event organiser Mercator Media.

The commercial marine and workboat exhibition is the largest of its kind in Europe and is a showcase for some of the industry’s top companies to buy, sell and network and to unveil pioneering new inventions.

This includes anything from passenger vessels to deep-sea diving and oil spill clean-ups. It attracts 7,500 professionals from 72 countries to view products and services.

Daily Echo:

Seawork chief Andrew Webster said there is "no alternative venue" to Mayflower Park

It took place in Mayflower Park for the first time last month after 18 years at the city’s docks.

But Southampton Commons and Parks Protection Society (SCAPPS) thinks the move may have breached a law passed in the 1980s.

That law, known as the Hampshire Act, outlines a number of the city council’s key responsibilities from the use of public land, bridge tolls and dredging.

The law also enshrines the council’s right to close Mayflower Park for nine consecutive days to host the Southampton International Boat Show. The society thinks that the closures for Seawork contravene this.

SCAPPS secretary Graham Linecar acknowledged the event’s economic importance but said “abuse” of the area should be stopped.

He said: “The park is the only green space where you can kick balls around for people in that part of the city.

“There are questions about the law, as to whether the city council were legally able to do what they did.”

SCAPPS representatives are meeting Southampton City Council boss Simon Letts next week to negotiate a solution.

The Labour leader said: “We are hoping to avoid a legal challenge.

“I have set up a meeting with them [SCAPPS] to see if we can find a way to make everyone happy.

“We are happy to work with Seawork, who bring visitors to the city, fill up the hotels and restaurants and we think it brings in £100m, and we don’t want to give that up.”

He added that Seawork pays the council tens of thousands of pounds to host the show at the park, but was unable to provide the exact amount.

Organisers say preparation is “already well underway” for Seawork 2017, its 20th anniversary.

Mr Webster said some delegations book their hotel five years in advance, and highlighted the importance of the marina built at Mayflower Park during the event.

“It’s due to the pontoons where harbourmasters and marine operations managers can come down, get on a pilot boat and try it and compare it,” he said. “You can’t do that anywhere else in the world.”

Cllr Jeremy Moulton, leader of the council’s Tory opposition, stressed Seawork’s importance to the city as a centre of the marine industry.

He said: “If there are concerns they need to be listened to. The park is there to be used but there needs to be a compromise and discussion so that it doesn’t impact on people who use it.”

Meanwhile Stewart Dunn, chief executive of Hampshire Chamber of Commerce said: “It’s vital to encourage Seaworks to stay in the city as it offers a terrific boost to the economy and jobs.

“If there is any contravention of a bylaw it needs to be resolved quickly before starting planning for next year.”

Southampton Commons and Parks Protection Society (SCAPPS) was founded shortly after the national Commons Preservation Society’s fight in the 1860s against enclosures of common land in the London area.

It is essentially a pressure group which aims to protect Southampton’s green areas from damage and encroachment and consists of members of community groups such as residents associations.

It has no formal statutory power but regularly objects to planning applications and council policies.

Mayflower Park is located on reclaimed land near the city’s Red Funnel terminal and is used to host events offering stunning views for people to watch cruise liners set sail from their home port. It also hosts music festivals, firework displays, circuses, radio roadshows, sporting activities and motorsport.