Answer-1 honest 99 liars

Explanation:
Given that choosing any two politicians one would surely be a liar and atleast one is honest.
So, considering the case of one honest politicians call him A.

Now for A we have 99 options to choose another politician and as given A is honest and also other one has to be a liar in that case , any politician we choose from 99 , he will be a liar for sure to justify the given conditions.
Therefore , only 1 is honest and 99 liars.