Maidstone Borough within Kent
 
Maldon Borough within Essex
 
Malmesbury Borough within Wiltshire
 
Marlborough Borough within Wiltshire
 
Melcombe Regis Borough within Dorset
 
Merioneth County
 
Middlesex County
 
Midhurst Borough within Sussex
 
Mitchell Borough within Cornwall
 
Monmouth Boroughs Borough within Monmouthshire
 
Monmouthshire County
 
Montgomery Boroughs Borough within Montgomeryshire
 
Montgomeryshire County
 
Morpeth Borough within Northumberland