But the £600,000 improvement scheme is already at the centre of a row between the town council and Suffolk County Council, which will carry out the work.

Town mayor Cllr Bill Burch said he was furious that final details of the scheme, which has been the subject of discussion for more than a decade, had been released to the media ahead of a council meeting on Monday when a senior highways engineer, Rod Sore, is due to make a presentation to councillors and answer questions.

"I can't answer any questions on it because I have not been sent the details," said Cllr Burch.

The improvement work is likely to take about three months but that will be spread over the next year to keep disruption to a minimum, particularly during the busiest race meetings and the Christmas period.

The current scheme was first unveiled at a public exhibition in Newmarket nearly two years ago along with 13 alternative proposals.

Since then, work has continued on the detailed design of the preferred option.

The biggest change from the current layout is that the town's historic clock tower will stand in its own paved precinct and, while the central island will not be like the one that was in place more than 30 years ago, it will contain a sculptural feature. The current design represents a clock face.

There are also changes to the road layout with no access to Exeter Road from the roundabout, only directly from the High Street.

Exeter Road will also become two-way from its junction with Fred Archer Way as far as Clocktower Mews to allow for deliveries and access to service roads.

Other aspects of the scheme include:

- Minor changes to the existing traffic lights at the Fred Archer Way/ Exeter Road/ Waitrose access to improve traffic flow especially for those trying to exit Waitrose superstore

- No right turns from the Waitrose access

- An over-run area to surround the central island area of the roundabout which will accommodate large vehicles by allowing them to cross the over-run area while turning. However, its surface texture will not encourage cars and smaller vehicles to use it

- A pedestrian precinct near the clock tower

- Up-lighting of the clock tower

- Installation of street furniture.

County councillor Guy McGregor, portfolio holder for roads and transport, said: "The scheme will be targeting the same issues that have driven the whole project to date, such as accident and casualty reduction, providing an improved gateway into Newmarket and promoting the economy of the town."

Newmarket county councillor Lisa Chambers said: "I know that local residents and shopkeepers in the area will be relieved to hear that the much-needed improvements are on the way," she said.