Historic mine workings found on the site of a contentious proposed housing development in Mirfield could force builders to revise the layout of their plan.

It is the latest twist in the long-running saga of Balderstone Hall fields, which is earmarked for 61 houses by Newcastle-based Bellway Homes.

Campaigners have battled for two decades to stop development at the site, close to grade II listed Balderstone Hall.

Now they have called on planning chiefs at Kirklees Council to undertake “detailed and conclusive surveys” to bring an end to the impasse.

Leading Conservative councillor Martyn Bolt said newly-discovered mine entries on the 11.4-acre site had led the Coal Authority (CA) to suggest that Bellway should amend its proposals.

Clr Martyn Bolt who did a sponsored bike ride to raise funds to fight housing plans for Balderstone Fields in Mirfield.

In an email to council planning officers the CA said seven suspected mining features did, in fact, appear to mine entries of unknown depth.

And in light of what it calls “coal mining legacy features” that have previously been identified it has pressed for “intrusive site investigations” to be carried out.

For the Coal Authority, Melanie Lindsley said the findings of intrusive site investigations “should guide the layout of the development.”

She added: “The Coal Authority would expect the layout to be revised to avoid building over, or within influencing distance of, any mine entries which are established as being.”

She advised that building over the top of, or in close proximity to, mine entries should be avoided and indicated moving one planned dwelling away from a mine entry “and its zone of influence.”

Balderstone Fields

The news will provide a boost to campaign groups as well as local politicians who have been in the vanguard of the anti-Bellway opposition.

The recent discovery of what is believed to be the remains of a 2,000-year-old Iron Age round house with a fortified entrance was described by Mirfield town councillor and Project Mirfield spokesman Steve Benson as “a game changer.”

The “constant pressure” applied by him and others was highlighted by Clr Bolt, who said the latest archaeological update was “a blow” to Bellway Homes’ plans.

“The matter which should concern residents throughout Kirklees is why this information has only come now after pressure and investigation by Mirfield town councillors,” said Clr Bolt.

“The site is the same, the developer the same, the planning authority the same and the Coal Authority the same as they have been for the last two decades while this site has kept raising its head.

“So why haven’t the Coal Authority and local planning authority demanded from the developer on this, and perhaps many other sites in the district for which mining was once a prevalent activity, detailed and conclusive surveys?

Mirfield Town councillor Steve Benson with his drone objecting to a Housing development on Balderstone fields,With his DJI phantom 1.

“Otherwise they risk approving building for which future occupants may have to pick up the cost in terms of subsidence or, worse, sink holes, some years down the line.”

He said the Coal Authority’s approach to the discovery of old mine workings represented “a clarion call” for all local groups to refer to it maps and other key local knowledge “to ensure Kirklees isn’t allowing development on land similar to this without a full and conclusive survey.”

The current plan represents the latest attempt by the housing firm to build on the site which is close to grade II listed Balderstone Hall. In 2015, minutes before councillors were due to consider a plan to build 130 homes, Bellway withdrew its application.

And it was defeated in 1999 when campaigners with action group Save Mirfield won a public inquiry to stop development. Prior to the start of the inquiry at Dewsbury Town Hall more than 800 people met on the fields to spell out the slogan ‘No Way Bellway’.