This proposal, wrote the fabulist, met with general applause, until an old mouse got up and  'That is all very well, but who is to bell the Cat?
The mouse's interruption was bordering on rudeness. 
mnli hypothesis: The mouse's interruption was bordering on rudeness.  premise: This proposal, wrote the fabulist, met with general applause, until an old mouse got up and  'That is all very well, but who is to bell the Cat?