[Grammar] to be a subject to / to be subject to

[englishhobby]

Are both expressions used in the meaning "to be affected by"? I have come across the one with the article (a) only in some textbooks, while dictionaries say "to be subject to" (without an article).

http://www.ldoceonline.com/dictionary/subject_2

Which one is correct?

 

[Rover_KE]

In that context, the one without 'a' is correct.