Possible Clues:

• Politician follows everyone into backstreet to see invention
• Unlikely tale
• Whopper
• Every way to penetrate politician's falsehood
• Hardly the tale of Tom Thumb, and may not be true
• Certainly not the talel of Tom Thumb - that's the height of improbability
• A highly questionable account
• It's hard to believe that this is not the tale of Tom Thumb
• Fairy tale suggesting Jack and the Beanstalk?
• Unbelievable yarn