What's more, it seems they COULD do it at Thornborough, using the Aggregates Levy funds (which they are empowered to distribute or spend), if they had the will...

"The Fund will support projects to develop the knowledge, understanding and appreciation of the historic environment that has been, or may be in the future, affected by aggregate extraction. The broad thrust of the projects supported by the Fund at English Heritage will fall into three main areas.....

.... In partnership with English Nature and Countryside Agency, to enable the targeted buying-out of old mineral permissions, for the benefit of the long-term management and sustainability of the historic environment."