A council is expected to allocate an extra £400,000 to a town regeneration scheme that has been heavily criticised by local businesses.
Contractors started digging up Market Place in North Walsham earlier in the autumn.
The project, already costed at £1.3m, will ban general traffic from the town centre during the day, will widen pathways, external and will install new bike racks.
North Norfolk District Council said the extra cash was needed because of the rising cost of fuel, labour and materials.
A council spokesman said: “The once in a lifetime investment in North Walsham’s historic centre is key to delivering vibrant and energised spaces, which have been designed specifically for markets and events to take place, increasing customer footfall and business opportunities."
The scheme will also install new crossings, seating and street planters.
The council's Liberal Democrat cabinet is recommended to approve the extra funding at a meeting, external on Monday.
The designs were first drawn up three years ago.
Colin Page, who has owned CD Page confectioners at Market Place for 21 years, said the scheme "goes against the character of the town".
"I think it was completely unnecessary from the start and I don't think it will achieve anything at all," he said.
"This is a pop-in town.
"People like to be able to pull in and out, park up, do their shopping and go away again."
Ian Jackson, who owns Sam's Pets nearby, said his deliveries were sky-high because people did not want to drive into the town during the construction.
Isaac Crass, manager at Express Printing and Stationery, said his sales dropped by about 50% after the market was closed off.
The council spokesman added: "This project has always been about increasing footfall and trade and providing new attractive places to visit, stay and shop."
North Walsham, which has its own Heritage Action Zone, has more than 100 listed buildings, external which mostly date from the 18th and early 19th centuries.
Much of the town was rebuilt after its Great Fire of 1600.