Exhibit (23)(a)

            Consent of Independent Registered Public Accounting Firm

We consent to the incorporation by reference in the Registration Statements
(Form S-8 No. 333-32229 and No. 333-58686) pertaining to the CMS Energy
Corporation Performance Incentive Stock Plan and Executive Stock Option Plan,
respectively, (Form S-8 No. 333-76347) pertaining to the Employee Savings and
Incentive Plan of Consumers Energy Company, in the Registration Statements (Form
S-3 No. 333-51932, No. 333-52560, No. 333-27849, No. 333-37241, No. 333-74958,
No. 333-45556 and Form S-4 No. 33-60007) of CMS Energy Corporation and in the
related Prospectuses of our report dated February 27, 2004, with respect to the
consolidated financial statements and schedule of CMS Energy Corporation and
subsidiaries included in the Annual Report (Form 10-K/A-1) for the year ended
December 31, 2003.

                                                         /s/   ERNST & YOUNG LLP

Detroit, Michigan
July 19, 2004