Exhibit 23.1

            CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We consent to the  incorporation  by reference in  Registration  Statement  Nos.
333-119491,  333-104230,  333-82230,  333-92003  and  333-13429  on Form S-3 and
Registration  Statement Nos. 333-119474,  333-53765,  333-40472 and 333-79151 on
Form S-8 of our reports  dated  February  28,  2006,  relating to the  financial
statements  and  financial  statement  schedules of KeySpan  Corporation  [which
report  expresses an unqualified  opinion and includes an explanatory  paragraph
related to (i) the adoption of FASB Interpretation  ("FIN") 46 "Consolidation of
Variable Interest  Entities,  an Interpretation of ARB No. 51" discussed in Note
1(P)  and (ii)  the  adoption  of FIN 47, "  Accounting  for  Conditional  Asset
Retirement  Obligations,  an interpretation of FASB Statement No. 143" discussed
in Notes 1(O), 1(P) and 7] and to management's  report on the  effectiveness  of
internal  control over  financial  reporting  appearing in this Annual Report on
Form 10-K of KeySpan Corporation for the year ended December 31, 2005.


/s/DELOITTE & TOUCHE LLP
February 28, 2006
New York, New York