Neither the old Marine station nor the old Harbour station is remotely derelict so it is hard to know what Charlie was referring to. Somebody ought to check his speeches for him before he puts his foot in it.
The Marine station, latterly Dover Western Docks, closed to passengers in 1994 following the construction of the Channel Tunnel. It was subsequently converted into Cruise Terminal 1 and is presently undergoing major restoration works.
http://www.disused-stations.org.uk/d/dover_western_docks/index.shtml
The Harbour station closed to passengers in 1927 following a gradual rundown after the construction of the Marine station, which also replaced the old Dover Town station by the Lord Warden hotel. The platforms and overall roof were removed but the station buildings remained in existence and in recent years have been used by P&O as a Marine Evacuation System training centre and kept in immaculate condition. The photo below is of the entrance hall which can hardly be described as derelict.
http://www.disused-stations.org.uk/d/dover_harbour/index.shtml