Exhibit 23 Consent of Arthur Andersen, LLP, Independent Accountants CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS As independent public accountants, we hereby consent to the incorporation by reference in this registration statement, as amended (Registration No. 333-53657) of our report dated January 25, 2001 included in KeySpan Corporation's Form 10-K for the year ended December 31, 2000. /s/ Arthur Andersen LLP ARTHUR ANDERSEN LLP New York, New York April 11, 2001