The Conservative leader of Buckinghamshire County Council, Martin Tett leads the consortium of councils that are anti-HS2.

BBC: Buckinghamshire election: Conservatives retain control

Buckinghamshire County Council awarded FCC Environment the job of building and operating the energy-from-waste facility at Calvert last July.

BBC: Artists impression of Calvert incinerator

The letter was signed by Mr Carter, Martin Tett from Buckinghamshire County Council and Hampshire County Council's leader, Ken Thornber.

BBC: Paul Carter