Acting In Dual Capacity- Barred By Law?

As we all know, advocates and solicitors ought to obtain a power of attorney from their clients including non-resident clients, in order to facilitate the Advocate's firm or Solicitor's firm to act in its professional capacity for the client. Many times, besides acting as Constituted Attorneys i.e. power of attorney holders, advocates also act as the advocates on record. The legal validity of this practice, which has become customary, has been questioned and debated upon in various judgments.

The principal issue in this scenario is whether an advocate can act as a Constituted Attorney of a party, and thereby be authorised to sign pleadings and affidavits on behalf of the suitor and also act and plead for the party concerned in the same litigation proceeding.