The Mayor of London has stepped in to stop 149 acres of marshland dubbed Bexley’s “jewel in the crown” being concreted over for a train interchange.

Sadiq Khan has ordered that an application to build a new rail freight interchange in Crayford Marshes be refused because it would be inappropriate use of greenbelt land.

There was opposition to the plans which would have seen a freight rail interchange on Crayford Marshes including a warehouse, new road access, and a bridge over the River Cray.

Plans, submitted by Roxhill Development, had been approved by Bexley Council but rejected by Dartford Council.

Dartford councillors voted unanimously against the plans.

In a letter to Bexley Council, Sadiq Khan said: “Having now considered a report on this case, I do not consider the proposal would achieve the modal shifts from road to rail freight within London envisaged within my Draft Transport Strategy, and therefore there are not demonstrable benefits for London which would outweigh the loss of London’s Green Belt.

“I direct you to refuse planning permission, under the powers conferred on me by article 6 of the above Order

“The proposal is inappropriate development in the Green Belt and very special circumstances have not been demonstrated which would clearly outweigh the harm to the Green Belt by reason of inappropriateness, and any other harm.”

More than 1,350 supporters have signed a petition demanding the plans be rejected.

The plans were rejected by Dartford Council because of the additional pressure it would put on the towns roads and the additional traffic to Bob Dunn Way.

Donna Zimmer, who campaigned against the plans for Friends of Crayford Marshes, said: “Although I was very pleased to hear that the London Mayor has directed Bexley Council to refuse the plans as they are inappropriate use of our Green Belt, our green space and the wildlife at Crayford Marshes are still not safe.

“Part of Bexley Council's Growth Strategy now wants to build a bypass through this area.

“These plans yet again would fragment what is left of our marshes destroying habitat for our wildlife including red-listed birds Skylark and Corn Bunting.”

Bexley’s Growth Strategy sets out proposals for enhancements to Erith and Crayford Marshes, dubbed the jewel in the crown by Councillor Stef Borella, to “improve quality and desirability.”

Bexley’s Growth Strategy’s deadline is Friday, July 28.