10 ILCS 5/10-8
Except as otherwise provided in this Code, certificates of nomination and nomination papers, and petitions to submit public questions to a referendum, being filed as required by this Code, and being in apparent conformity with the provisions of this Act, shall be deemed to be valid unless objection thereto is duly made in writing within 5 business days after the last day for filing the certificate of nomination or nomination papers or petition for a public question, with the following exceptions:
Any legal voter of the political subdivision or district in which the candidate or public question is to be voted on, or any legal voter in the State in the case of a proposed amendment to Article IV of the Constitution or an advisory public question to be submitted to the voters of the entire State, having objections to any certificate of nomination or nomination papers or petitions filed, shall file an objector's petition together with 2 copies thereof in the principal office or the permanent branch office of the State Board of Elections, or in the office of the election authority or local election official with whom the certificate of nomination, nomination papers or petitions are on file. Objection petitions that do not include 2 copies thereof, shall not be accepted. In the case of nomination papers or certificates of nomination, the State Board of Elections, election authority or local election official shall note the day and hour upon which such objector's petition is filed, and shall, not later than 12:00 noon on the second business day after receipt of the petition, transmit by registered mail or receipted personal delivery the certificate of nomination or nomination papers and the original objector's petition to the chair of the proper electoral board designated in Section 10-9 hereof, or his authorized agent, and shall transmit a copy by registered mail or receipted personal delivery of the objector's petition, to the candidate whose certificate of nomination or nomination papers are objected to, addressed to the place of residence designated in said certificate of nomination or nomination papers. In the case of objections to a petition for a proposed amendment to Article IV of the Constitution or for an advisory public question to be submitted to the voters of the entire State, the State Board of Elections shall note the day and hour upon which such objector's petition is filed and shall transmit a copy of the objector's petition by registered mail or receipted personal delivery to the person designated on a certificate attached to the petition as the principal proponent of such proposed amendment or public question, or as the proponents' attorney, for the purpose of receiving notice of objections. In the case of objections to a petition for a public question, to be submitted to the voters of a political subdivision, or district thereof, the election authority or local election official with whom such petition is filed shall note the day and hour upon which such objector's petition was filed, and shall, not later than 12:00 noon on the second business day after receipt of the petition, transmit by registered mail or receipted personal delivery the petition for the public question and the original objector's petition to the chair of the proper electoral board designated in Section 10-9 hereof, or his authorized agent, and shall transmit a copy by registered mail or receipted personal delivery, of the objector's petition to the person designated on a certificate attached to the petition as the principal proponent of the public question, or as the proponent's attorney, for the purposes of receiving notice of objections.
The objector's petition shall give the objector's name and residence address, and shall state fully the nature of the objections to the certificate of nomination or nomination papers or petitions in question, and shall state the interest of the objector and shall state what relief is requested of the electoral board.
The provisions of this Section and of Sections 10-9, 10-10 and 10-10.1 shall also apply to and govern objections to petitions for nomination filed under Article 7 or Article 8, except as otherwise provided in Section 7-13 for cases to which it is applicable, and also apply to and govern petitions for the submission of public questions under Article 28.
10 ILCS 5/10-8