Havering Council has threatened to use its 800-year-old charter to prevent neighbouring Brentwood from expanding its market.

Brentwood has held a series of regular market days in its town centre in recent years, but plans to expand the scheme could be challenged.

Havering has pledged to use the recognition granted by King Henry III in 1245 to stop its rival’s extension.

The legal minimum distance between markets is six and two-thirds of a mile – an ancient law based on how far a sheep could be walked in one day.

Cllr Robert Benham, Havering’s cabinet member for community empowerment said: “We are very proud of our market and it attracts visitors from miles around.

“The charter we have is over 800 years old and held by the British Library.

“We will use our Charter Rights to stop other markets being set up in the area it covers.”

Romford historian Brian Evans, who now lives in Brentwood, said: “The actual charter is from 1465, but the rolls were written in 1245.

“It has been used before to block other markets in the area – it was used against Barking over its market about 20 years ago.

“The charter is still legally valid and it has been enshrined in later law.”

He added that Brentwood’s market was on its main road but it was “quite small”.

Havering Council’s website boasts: “That six and two-third mile marker remains the minimum distance between markets. It is the legal bedrock on which Romford has successfully fought off the setting up of other markets.”

But Havering could find Brentwood to be a more formidable opponent than Barking in the courts - its council says it also has a charter granted by Henry III dating back to 1227 – almost 20 years before Romford’s.

Cllr Mark Reed, the chairman of Brentwood Council’s retail, community and culture panel, said: “The public are very keen to see our vibrant market in Brentwood developed. This market has been running for around two years.

“We are working with the market organiser to improve its range and quality and so make the shopping experience even better in Brentwood.”