I don't know how many exactly, as I've always had maxed Charm or Intimidate when I got to him, but I know it has to be more than 2 at least. (I've had just 2 in those skills and the option isn't available.)
i just passed where you are buddy. make sure you have 4-5 in each charm and intimidation first. try going to the other planet they send you to in order to level up. then try. anyone know what that stuff does for you?