At any time after the institution of a proceeding and before it has been submitted to the Secretary for final consideration, the Secretary or the examiner as defined in Sec. 47.2(i)(1) may, upon petition in writing and for good cause show, permit any person to intervene therein. The petition shall state with preciseness and particularity:
(a) The petitioner's relationship to the matters involved in the proceeding; (b) the nature of the material the petitioner intends to present in evidence; (c) the nature of the argument the petitioner intends to make; and (d) any other reason that the petitioner should be allowed to intervene. [10 FR 2209, Feb. 27, 1945, as amended at 60 FR 8459, Feb. 14, 1995; 64 FR 38107, July 15, 1999]