Reference for Megillah 3:20

רבי יהודה אליבא דמאן אילימא אליבא דר"ע אפילו בזמן הזה איתא להאי תקנתא

Which opinion is R’ Yehuda following? Shall I say he follows the opinion of R’ Akiva? This cannot be, because [according to him] the regulation is in force in these days also.

Jastrow