Exhibit 5.1 Sidley & Austin One First National Plaza Chicago, Illinois 60603 April 22, 1994 Iowa-Illinois Gas and Electric Company 206 East Second Davenport, Iowa 52801 Re: 2,000,000 Common Shares ----------------------- Ladies and Gentlemen: We refer to (i) the proposed issuance and sale by you (the "Company") of up to 2,000,000 of the Company's authorized but unissued Common Shares, $1.00 par value (the "Common Shares"), pursuant to the Company's Dividend Reinvestment and Share Purchase Plan (the "Plan") and (ii) the Registration Statement on Form S-3 (the "Registration Statement") being filed by you with the Securities and Exchange Commission (the "SEC") under the Securities Act of 1933, as amended (the "Securities Act"), with respect to such issuance and sale. We are familiar with the proceedings to date with respect to the proposed issuance and sale of the Common Shares and have examined such records, documents and questions of law, and satisfied ourselves as to such matters of fact, as we have considered relevant and necessary as a basis for this opinion. Based on the foregoing, we are of the opinion that: 1. The Company is a corporation duly organized and existing under the laws of the State of Illinois. 2. The Common Shares will be legally issued, fully paid and non-assessable when (i) the Registration Statement shall have become effective under the Securities Act and (ii) certificates representing the Common Shares shall have been duly executed, countersigned and registered and duly delivered upon payment of the consideration therefor pursuant to the Plan. Iowa-Illinois Gas and Electric Company April 22, 1994 Page 2 We do not find it necessary for the purposes of this opinion, and accordingly we do not purport herein to cover, the application of the securities or blue sky laws of the various states or the District of Columbia to the sale of the Common Shares. In addition, in rendering the opinion expressed in Paragraph 2, we do not purport to cover and are not expressing any opinion with respect to the applicability to the Company or the proposed issuance and sale of the Common Shares of the provisions of the Public Utility Holding Company Act of 1935, as amended, or the Investment Company Act of 1940, as amended, each of such Acts being the subject of an opinion of even date herewith of Brent E. Gale, Esq., General Counsel of the Company. This opinion is limited to the laws of the United States of America (except as noted above) and the State of Illinois. We hereby consent to the filing of this opinion as Exhibit 5.1 to the Registration Statement and to all references to our firm included in or made a part of the Registration Statement. Very truly yours, /s/ Sidley & Austin