The 600-year-old law bans anyone from holding a market within six and two-thirds miles of the one in South Shields.

It allows a market operator to object to a rival venture anywhere within the distance a trader or mule could reasonably be expected to walk each way - held to be six-and-two-thirds miles.

The North East Chamber of Commerce's Sunderland committee agreed last year to look at mounting a challenge to the law.

Now organisers say they have received legal advice that the law applies to the distance it would be necessary to actually travel on the ground, rather than as-the-crow-flies and are pressing ahead with plans for a market in Sunniside.

"If you run an AA route check, the distance from Shields market place is 7.5 miles, so we are proceeding on this basis," said committee chairman Mick Thurlbeck.

"Our intent is to have at least one market before Christmas to test the water. If successful, we hopefully can negotiate with partners to stage the market on a regular basis, say the first Saturday of each month."

Now the committee is talking to other towns across the region to ensure any market in the city does not clash with what is already on offer.

"We are busy researching what others are doing - Northallerton, Morpeth, Alnwick - to establish a niche in the events calendar."

A farmers market offering locally-sourced produdce is the front-runner but business bosses are also looking at introducing themed markets to tie in with events such as next year's Irish Festival.

"We have not ruled out the possibility of temporarily moving the market to other areas such as Park Lane in the future, again to coincide with other city events," said Mick.

"We must be one of the last cities or towns in the country to offer this facility to the public.

"So now is time for change."