Traders in The Hornet and East Street have seen a massive downturn in customers since the highways workers took up residence on the pavements and roads outside their shops around eight weeks ago.

Pedestrians and wheelchair users have been left to negotiate cones and barriers as they desperately try to make their way around.

But traders have said many have simply been put off from visiting their stores.

Spar shop worker Chirag Jogi said: "We have definitely seen a reduction in the number of people coming in. I would say at least 30 to 40 per cent fewer people.

"We have had a problem with deliveries, too. They now have to park by New Look and come across the road to us. It is quite difficult for them."

And they are not alone in their plight – Culpeper UK Ltd, which specialises in acupuncture, has also witnessed a distinct downturn in trade.

"It has definitely gone down," said manager Bernice Heydenrych.

"We have seen a lack of people walking past our door. It is very confusing – people just don't know where to walk.

"It wasn't too bad when they were on the other side of the road. It is since they have been doing the paving on this side we have really noticed it."

And it is not just the stores themselves that are fed up – customers are frustrated at the upheaval, too.

"Customers ask 'what on earth is going on?' They are not happy about it," Fired Earth manager Laura Asmar said.

"We have people who collect tiles and paint after they have ordered it, which can be heavy, but they now complain they have nowhere to park.

"They are used to parking for free in the bays outside but now have to pay to park in the cattle market car park. That does not go down very well."

Traders and customers face an extra month of disruption because of additional unplanned drainage works.

This means instead of being largely finished by the end of the month, work is now expected to finish at the end of June.

A spokesman for West Sussex County Council apologised for the disruption.

"The construction works started on March 10 and were originally due to be substantially complete by the end of May. However, on digging down, we found issues with some of the drainage

"That work has delayed the paving above it.

"There have also been issues with a number of underground services being discovered in uncharted places – and squeezed into quite shallow depths – that have required careful attention."