The given cipher text is this:
CWT VIFTDBOTBC NDINIAMRA GTDT DTYTQCTS PK CWT RMPIED ANIZTAOMB MA XDDTRTFMBC CI CWT NDIPRTOA CWMC CWT RXPDMDK ATDFXQT XA UMQXBV
Using frequency analysis and some trial and error I have the plaintext:
THE GOVERNMENT PROPOSALS WERE REJECTED BY THE LABOUR SPOKESMAN AS IRRELEVANT TO THE PROBLEMS THAT THE LIBRARY SERVICE IS FACING
I have been told that this ciphertext has been obtained using a mono-alphabetic (substitution) cipher that is not an affine cipher. However I can't seem to find the key, I have tried using a 2-by-2 hill cipher and a Caesar Cipher but neither work. There is no common link I can find between the plain text alphabet and the Cipher text alphabet below:
a b c d e f g h i j k l m n o p r s t u v w y m p q s t u v w x y z r o b i n d a c e f g k
where q,x,z have no known ciphertext encryption.