Conn. Agencies Regs. § 5-273-11
Whenever a notification has been filed with the board under subdivision (1) of subsection (a) of Section 5-275 of the Connecticut General Statutes any other employee organization may file with the board a challenge in writing which states that ten percent (10%) or more of the employees have expressed the desire to have the intervenor as exclusive representative in writing in the manner specified in subdivision (2) of subsection (a) of Section 5-275 of the Connecticut General Statutes. Such challenge shall be deemed to include a petition for intervention in the proceedings and shall, in addition to the requirements specified in this section, conform to the requirements set forth in section 5-273-10(a), supra. A challenge must be filed within thirty (30) days of the filing of the notification.
Conn. Agencies Regs. § 5-273-11