Transport Secretary Chris Grayling has said it is “inconceivable” that the Copdock Mill interchange between the A14 and A12 south of Ipswich will not be rebuilt over the medium term.

Its reconstruction to provide an easy link between Suffolk’s two busiest roads is a key demand of the Suffolk Chamber of Commerce’s “No More Delays on the A14” campaign.

And Mr Grayling seemed to back their calls during a visit to Suffolk.

When asked about that junction, the Secretary of State said: “Highways England is still drawing up its programme for the next few years – and much of its current effort is concentrated on the major rebuilding of the A14 between Cambridge and Huntingdon.

“But I know the Copdock Mill interchange and I know the bottleneck it proves to be for traffic on an almost daily basis. It is inconceivable that it would not be rebuilt to keep traffic moving better.”

Highways England is currently drawing up its second Route Improvement Strategy (RIS2) covering major projects it would like to see carried out between 2020 and 2025.

The “No More Delays” campaign is pressing for major improvements to seven junctions on the A14 in Suffolk to be included in RIS2 – but the Copdock Mill is the largest single challenge.

Designing a new junction that would allow traffic to move between the A12 and A14 without stopping – and provide a link into Ipswich – would be very challenging and very expensive. It has been said that would cost more than an entire northern by-pass for the town, well over £150m. And the roadworks could take well over a year.

Suffolk Chamber policy director Nick Burfield said the comments by Mr Grayling were, while stopping short of an official promise, hopeful for the future.

He said: “It is certainly encouraging that he is aware of the issues. We are campaigning for seven junction improvements but we are aware Copdock Mill is the ‘big one’ in terms of cost – but if Highways England wants to turn the A14 into an expressway it will have to be improved.”

Mr Burfield said there had been some initial proposals drawn up for an amended Copdock Mill junction design: “It would be a challenge but it is not impossible,” he said.