EXHIBIT (23) (a)



            Consent of Independent Registered Public Accounting Firm


We consent to the reference to our firm under the caption "Experts" in the
Registration Statement on Form S-3 and the related Prospectus of CMS Energy
Corporation and to the incorporation by reference therein of our reports dated
March 7, 2005, with respect to the consolidated financial statements of CMS
Energy Corporation, CMS Energy Corporation management's assessment of the
effectiveness of internal control over financial reporting, and the
effectiveness of internal control over financial reporting of CMS Energy
Corporation, included in its Annual Report (Form 10-K) for the year ended
December 31, 2004, and the related financial statement schedule of CMS Energy
Corporation included therein, filed with the Securities and Exchange Commission.


                                        /s/ Ernst & Young LLP

Detroit, Michigan
June 2, 2005