Who may file a complaint?

Representation of the People Act, 1976

Scrutiny.—(1) The candidates, theirelection agents, 1[the proposers and seconders and one other person authorisedin this behalf by each candidate] [and an elector who has filed an objection tothe nomination of a candidate,] may attend the scrutiny of nomination papers,and the Returning Officer shall give them reasonable opportunity for examiningall nomination papers delivered to him under section 12: [Provided that anelector who has filed an objection to the nomination of a candidate shall onlyattend the scrutiny of the nomination paper of that candidate.]

(2) The Returning Officershall, in the presence of the persons attending the scrutiny under sub-section(1), examine the nomination papers and decide any objection raised by any suchperson to any nomination.

Source:

http://ecp.gov.pk/ElectionLaws/Volume-I.pdf