Government plans to charge tolls to help fund an upgrade of the A14 have been “badly conceived and poorly executed”, according to campaigners opposed to tolling.

In a letter to Chancellor George Osborne, leaders of the No Toll Tax on Suffolk campaign, launched by Suffolk Chamber of Commerce, claim that, with no proper cost-benefit analysis having been carried out, there is no reliable case for introducing the charges.

Stephen Britt, chairman of Suffolk Chamber’s transport board, and John Dugmore, the chamber’s chief executive, also complain in the letter that the consultation process over tolling, which closed last week, was seriously flawed in being too short and largely confined to Cambridgeshire, where the work is to be carried out.

The Government’s proposals include improvements to the Cambridge section of the A14, which would remain toll-free, and the construction of a new section of road south of Huntingdon which would be the subject of tolls between 6am and 10pm.

Part of the existing elevated section of the A14 in Huntingdon would be demolished, with weight restrictions on the town’s remodelled road network leaving lorry drivers with the choice of paying the toll or taking a lengthy diversion.

The No Toll Tax for Suffolk campaign, which has been backed by company bosses and business groups from across the county and beyond, reflects concerns that businesses in the region will suffer a disproportionate cost burden.

“A toll will distort competition between businesses from East Anglia and competitors elsewhere which will have lower transport costs to get to market,” says Mr Britt in the letter to the Chancellor.

“Businesses in the region are likely to suffer economic loss as a result with negative impacts for growth and employment.”

“Our members tell us that a toll would have a significant negative impact on inward investor confidence and on future inward investment. We have already been made aware of the plans of one major manufacturer to relocate out of the county should a toll be imposed.”

Concerns about the consultation process highlighted in the letter include complaints that the consultation period was “too brief to allow for meaningful engagement” between the Highways Agency and affected businesses and that all of the Highways Agency’s eight public exhibitions during the consultation period were held in Cambridgeshire, with no formal consultations scheduled for Suffolk, Essex or Norfolk.

The letter also says the Government has failed to make a convincing case for tolls, with the potential impact of the charges not having been addressed.

“No proper cost benefit analysis has been undertaken by the Government of the economic impact of the toll on businesses in the area of the toll as well as either side, including East Anglia, all of which will be affected by its introduction through higher costs and/or congestion on alternative routes,” the letter says.

“There is therefore no evidence to demonstrate clearly that the revenues would outweigh the wider costs and no relative basis upon which to introduce tolls.”

“As support grows and grows against tolling of the A14, it is more important than ever that the clarion call from local firms is heard loud and clear in Westminster.” said Mr Dugmore. “Our letter to the Chancellor makes it clear that the proposals being put forward are not acceptable and will be a tax on the Suffolk economy.”