PLANS to build 600 houses in Chepstow have been disrupted after councillors and planning officers discovered an error in the planning application.

Traffic from the Mabey Bridge site off Station Road has been an issue of concern for locals from the start, and now it has come to light that there may be 'thousands' more traffic movements in town after the build than first thought.

The application, submitted by Mabey Bridge Ltd, was found to have used data from a 2001 census instead of the most recent 2011 edition, a 14 per cent difference in numbers. These figures were presented to the town council at a meeting towards the end of last year, before they gave their recommendation for approval of the plans to Monmouthshire County Council (MCC).

"My concern is that misleading figures may have swayed our decisions initially," said Deputy Town Mayor Councillor Dale Rooke. "There are reams and reams of things that the developers haven't done that MCC are now asking them to do and it is very relevant that we revisit this issue.

"The figures are ten years out of date, there is a 14 per cent difference between the two, that's thousands of traffic movements. This could mean that the figures we were quoted originally could be greatly exacerbated. It's a different ball game now."

Cllr Peter Farley added: "This is such a significant development for the town, it is necessary we should be prepared to dedicate an entire meeting to it. We do need to start again as far as I can see."

Chepstow is currently under pressure at peak times from the volume of traffic backing up around the A48 junction near Tesco, and on Hardwick Hill. Pressure is also on from the Welsh Government to address pollution in the town.

Cllr Armand Watts said: "When the information was presented to us, they were adamant that the majority of people work and live in the town."

"But the fact is that most people who live in Chepstow commute to Cardiff or Bristol.

"They were passing off figures that were inaccurate to the committee and I don't like it, it's unacceptable.

"We as a council are under scrutiny more than ever, and there is such as lot of money involved here. This is such a significant development in the heart of our town and if we get in wrong we'll be open to a huge amount of scrutiny."

Councillors decided to hold a special meeting on the issue, in the words of Cllr Rooke, "to really nail it down once and for all". Organisers will look to include developers, MCC, representatives from schools, social services, those concerned with other proposed developments in town around Tutshill and Sedbury, and members of the public. A date has yet to be announced.

The Mabey Bridge site's project manager Andrew Leitch, said: "We didn't use the 2011 census because at the time, the part of it we needed was not available to us.

"We are working alongside MCC on almost a weekly basis to provide them with the information they need, and we are also working alongside the Welsh Government to bring together more information about traffic in the town.

"Traffic movement was always going to be the most contentious issue with this application, but I don't believe this is going to set us back. We have been working for about two years to make sure all our information is viable, and we are being careful and helpful.

"We'd like people to look at this development in the most positive way possible. There has been no attempt to pull the wool over anyone's eyes and we would be happy to speak at the next meeting."

A Monmouthshire County Council spokesperson said: "The council and Welsh Government have requested that the applicant's consultants use the latest census data for accuracy and to illustrate the complete picture.  We are unable to comment about traffic figures until the additional technical assessment has been submitted in support of the planning application transport assessment".