After the trip to Versailles to see the king and queen, Defarge tells the mender of roads that “you are the fellow we want.” What does Defarge mean by this? (Book 2 Chapters 14-16)

The mender of roads has the right information that the Defarges want.

You are the fellow we want,” said Defarge, in his ear; “you make these fools believe that it will last for ever. Then, they are the more insolent, and it is the nearer ended.”