The failure by a trial court to inform accused persons of their constitutional right to legal representation as required by section 163A(1) of the Criminal Procedure and Evidence Act read with section 191, and section 69(1) of the Constitution, is an irregularity so fundamental and serious that it is fatal to the proceedings. Such failure amounts to an irregular and illegal departure from the formalities, rules and principles of procedure in accordance with which the law requires a criminal trial to be initiated and conducted, resulting in proceedings that are not in accordance with real and substantial justice and causing a substantial miscarriage of justice. The right to legal representation is a substantive constitutional right, not merely a procedural formality, and is the cornerstone of a fair trial. Where such a fundamental irregularity occurs, the conviction must be set aside without reference to the merits of the case.