Bungling utility bosses have ensured a bank holiday nightmare for motorists by overrunning on roadworks.

The gas pipe replacements on Brighton seafront should have been finished two weeks ago but Southern Gas Networks (SGN) didn't take into account complications caused by the proximity of businesses in the arches beneath Kings Road.

The junction with West Street will be reduced to one lane eastbound as hundreds of thousands of visitors flock to the city at the weekend.

The utility company tried to blame "unforeseen circumstances" when confronted by The Argus over the issue early yesterday. It has since changed its story and admitted it knew about the difficulties it would face before the roadworks started.

Brighton and Hove's tourism centre has predicted a bumper influx of visitors this summer. But the business community said last night it was expecting losses of thousands of pounds as tourists shunned the city in favour of more accessible destinations.

Tony Mernagh, executive director of the Brighton and Hove Economic Partnership, said: "I'm very worried about the long-term impact these roadworks are having and which are costing business a lot of money."

It will be the second time this year roadworks have caused severe bank holiday traffic jams.

Restaurants in Kings Road and taxi drivers who would normally use the seafront say they are losing money.

Mr Mernagh said: "It has unfortunately become inevitable this city will be gridlocked on bank holidays.

"Our 8.5 million visitors a year, about half of whom I estimate arrive by car, will start going elsewhere."

Roberto Savvides, manager of The Regency restaurant on the seafront, estimated takings were down 25 per cent compared with the same period last year because of the roadworks.

He added: "We are losing a lot of business because people are cancelling bookings. They are calling ahead to ask if the queues of traffic are still bad and then cancelling."

Brighton taxi driver Michael Doyle said: "It's completely inconvenient because we are sitting in traffic for ages and quite often when we get to the place to pick up the customer they are gone because it has taken so long."

Alan McCarthy, Brighton and Hove City Council's chief executive said: "It is very disappointing and it is likely to cause disruption to people but the message is Brighton is still open for business and we would urge people to use alternative routes to the seafront.

"The gas company has told us it needs to do the work over the bank holiday and we have to go along with it, we have little other choice."

Roadworks are often suspended over bank holidays to ease congestion but SGN decided to press on at Kings Road.

A spokesman for SGN said: "I can only apologise. Nobody wants the road being dug up but it is essential. The pipes are worn out. We are going to push ahead to get this job finished as soon as possible.

"We have had to dig very, very carefully because there are businesses directly beneath the seafront so we had to be responsible in terms of noise as well as to avoid causing any damage. That slowed us down a few days."

The joint mains replacement works began on February 20 and were scheduled to last 12 weeks. Contractors are laying long-life polyethylene pipes to replace old metal ones.

Over Easter more than 20 routes were obstructed in Brighton and Hove, including the A23 London Road.

The situation shows no sign of improving. Brighton and Hove City Council has an extensive agenda of works planned throughout the summer.