The Times claimed that the number boycotting never reached a critical mass that would have threatened the integrity of its list.
The boycotting was arranged by an opposing firm that did not believe in the integrity of the list. 
mnli hypothesis: The boycotting was arranged by an opposing firm that did not believe in the integrity of the list.  premise: The Times claimed that the number boycotting never reached a critical mass that would have threatened the integrity of its list.