(a) An amendatory ordinance altering the boundaries of the legislative districts established pursuant to this article shall not be submitted to the registered voters until the ordinance has been submitted to the planning commission of the city or, in absence of a planning commission, to the legislative body of said city for an examination as to the definiteness and certainty of the boundaries of the legislative districts proposed.
(b) An amendatory ordinance altering the boundaries of legislative districts shall comply with the requirements and criteria of Section 21130 of the Elections Code.