Urgent investment is needed in the coastal towns of Shoreham, Worthing, Littlehampton and Bognor Regis, say development experts.

The towns have been highlighted in a far-reaching report from planning gurus at the South-East England Development Agency (Seeda).

The report made a string of recommendations to secure the future economic success of the region.

In West Sussex, the Regional Economic Strategy focused on removing bottlenecks on the A23 and A24 at Arundel, Worthing and Chichester.

Outdated seaside town centres needed a complete revamp and rail services on the Arun Valley line needed improving, it said.

High speed broadband internet technology was identified as a key to improving the economic growth in the county.

Low cost housing for key workers in Crawley, Horsham and Mid Sussex was essential in order to address labour shortages.

The quantity and quality of business parks along the coastal strip needed to be improved and Shoreham Harbour redeveloped.

Seeda's strategy sets the vision, priorities and key actions needed during the next ten years and has been backed by the South-East England Regional Assembly and the Government.

One of the most controversial issues examined was the proposed second runway at Gatwick.

The report said the decision to rule out further development at Gatwick until 2009 meant the airport was not fulfilling its potential and the economic impact of both having and not having a second runway needed to be assessed.

The Government has been forced to introduce further airport consultation options after losing a court battle last summer to miss Gatwick off the list of airports earmarked for expansion.

Seeda said the airport's prosperity was a major influence on the economies of towns within a 30-minute drive and, along with the money generated in Brighton and Hove, was critical to economic growth across the South-East.

The report said without a second runway at Gatwick valuable international business would leak away, spelling doom for the economic growth of the area.

Newhaven port should expand with better links to Gatwick, improvements were needed to the A21, A259 and A27 and an international centre of excellence in management and technology education should be set up.

One of Seeda's highest priorities, along with an in-depth look at Shoreham, Worthing, Littlehampton and Bognor Regis, was to see a building of world-class design replace the much-criticised Brighton Centre during the next ten years.

The development would provide world-class conference facilities and be capable of supporting the cultural and leisure regeneration of the city.

Hove MP Ivor Caplin called the Brighton Centre "a hallmark of Sixties and Seventies architecture, which frankly the seafront could do without."

He said: "What we must do is keep Brighton as the best conference venue, not just in the South-East but in the UK, because it accounts for 10,000 jobs."

The city's transport network was described as overburdened and a tram system was highlighted as a possibility for the future.

The report said the city was characterised by pockets of deprivation, highlighting East Sussex as being one of the poorest sub-regions in the South-East and suffering some of the worst deprivation in the UK.

One of the highest priorities in East Sussex was to reinstate the rail line between Lewes and Uckfield, a move that would improve access to Hastings and Bexhill and enable their economies to grow.