Has the Constitutional Council come to function primarily, as a third legislative chamber?

The decision to create a Constitutional Council in 1958 was based on the expectation that it would separate and completely break-off the era of the Fourth Republic from that of the Fifth Republic. The fourth republic was based on the principle of the parliaments sovereignty, which enabled the parliament to pass any law on any matter, as well as the Prime minister to issue decrees at his discretion. The Fifth republic ended this principle.

The Constitutional Council was the institution that finally decided, on which matters the parliament reserved the right to pass laws. One cannot examine or merely appreciate the legislative process in the French State, without assessing the direct and indirect functions and significance of the Constitutional Council which, admittedly, has come to function as a type of the third chamber of the French Parliament….(short extract)