Shopkeepers in a Berkshire town say their takings have been hit hard because road and pavement works are keeping customers away.
The £180,000 scheme to improve the centre of Thatcham started in March but its completion has been delayed until July after a gas main was unearthed.
Traders claim takings are down by as much as 40%.
West Berkshire Council said the project will make the town more attractive and bring in new shoppers.
Stephen Walker, from the Family Bookshop, said: "It has reduced our footfall considerably and my takings have been down by up to 40%.
"There are also fewer people coming into Thatcham."
Christian Martin, from the Cook & Butcher shop, added: "During the main bulk of the work when they shut The Broadway we lost about 25 to 30% in that three-week period.
"It was quite a considerable impact."
The council said the revamp will provide a "big boost" to the area.
Councillor Pamela Bale added: "This scheme will be a great improvement to the centre of Thatcham and should make it all the more attractive to visitors and shoppers.
"Clearly it is disappointing that this unexpected discovery [gas main] has held up progress but we are working hard to finish the scheme as quickly as possible."
Traders have also raised fears about a smaller project which is scheduled to take place in the High Street in the autumn.