Whenever a vacancy shall occur in either house of the General Assembly on the same day as the filing of a preliminary reapportionment plan by the Legislative Reapportionment Commission or during the period between such filing and the date that a final plan attains the force of law, the presiding officer of the house shall have the authority, notwithstanding any other provisions of law to the contrary, to delay the issuance of a writ of election until ten days after the date the final plan attains the force of law.
25 P.S. § 2778a