Exception.

If the action challenges the legality, validity or constitutionality of a proposed constitutional amendment, the defendant shall plead within three days after service of the original notice. [C31, 35, §11121-d1; C39, § 11121.1; C46, 50, 54, 58, 62, 66, 71, 73, 75, 77, 79, 81, §619.2 ] Referred to in §619.3