National Highways has apologised after more than 460 private email addresses were included in an email publishing the findings of the recent Copdock Interchange consultation.

More than 627 online surveys were completed in addition to 224 emails during the six-week period around the two options proposed to improve Junction 55, which suffers from congestion and poor journey reliability.

The 82-page report breaks down the response which found 64% in favour of option four and 22% for option one, though concerns were raised about both proposals.

National Highways shared the release of the findings in an email but sent it openly containing hundreds of private email addresses by accident.

James Goodman, National Highways project manager, said: "We're taking the issue very seriously. The error has been raised with our GDPR compliance team and we will be reissuing guidance on data protection to the whole team, whilst also undertaking an internal review of how this occurred."

In October, the agency put forward two options which was felt would improve the junction and reduce the impact on national and international-based businesses.

Option one is to increase the capacity of the existing junction to help accommodate future demand by widening the circulatory carriageway and providing free flow left turn lanes at three of the four entry arms.

Option two - named option four by National Highways - would involve building a new free-flow two-way grade-separated link road. The aim would be to decrease the volume of traffic at the existing junction by removing the A12 (South) to A14 (East) (and vice versa) movements onto separate link roads.

There is no funding committed to the project

Those in favour of option one said it would help improve journeys but were sceptical it would make the road network safer and support economic growth.

Feedback showed many thought the option would reduce traffic through local villages and improve connectivity for walking, cycling or horse riding.

Those against option four highlighted the cost of the project and the impact on the Belstead community, wildlife and noise and air pollution if the project was pursued.

The matter has not been passed on to the Information Commissioner's Office due to it not meeting National Highways threshold.

Deputy leader of Suffolk County Council Richard Rout, who owns land with his mum near Belstead Hall and Belstead Meadows, said the report made plain residents' concerns about option four and the environment around Junction 55.

Mr Rout, who was speaking in a personal capacity, said: "It is fundamentally a choice between which we see as more important - roads or the environment.

"There is no environmental or ecological argument for Option 4; it will destroy thousands upon thousands of trees, destroy the habitats of protected species and valuable natural corridors. It is fundamentally at odds with nationally and locally stated environmental ambitions.

“66% of email respondees opposed option four. There is far less opposition to option one, which delivers some improvement to Junction 55 at a fraction of the cost - both environmental and financial."

Many comments said the option would allow "meaningful economic growth" in and around Ipswich and the Port of Felixstowe.

The report said: "The proposals for improvements at Junction 55, Copdock Interchange are designed to increase capacity and improve journeys along the A12 and A14 corridors. There are also aims to help boost economic growth and development opportunities within the Ipswich area, including at the Port of Felixstowe."

Mr Rout disagreed, he said: “Equally shockingly, the consultation document states that the purpose of the scheme is not to encourage people into Ipswich.

"If hundreds of millions of pounds is to be spent on infrastructure around Ipswich it should be to support our county town, the communities around it, and access into and out of Ipswich. It should not be spent to serve the interests of out of county haulage firms.

“At a time of a cost of living increase, belt-tightening, and huge uncertainty we need to be supporting ordinary people, Ipswich and the neighbouring communities, not spending vast amounts on a vanity scheme that will shave five to eight minutes off journey times for lorries heading in and out of Essex.”

A number of respondents set out ideas on how they felt the scheme could be adapted and improved, including the merging of the two options as well as the removal of options two and three.

National Highways said: "Each chosen option fulfilled an approach to solving the problems at the junction providing meaningful alternatives to each other. Option 1 was best for creating capacity at the junction. Option 4 was the best for taking traffic away from the junction thereby enabling better use of current capacity."