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  22,  2007,  relating to the  financial
statements and financial statement schedule of KeySpan Corporation (which report
expressed an unqualified  opinion and included an explanatory  paragraph related
to (i) the  adoption of  Statement of  Financial  Accounting  Standards  No. 158
"Employers'  Accounting for Defined  Benefit  Pensions and Other  Postretirement
Benefit  Plans"  discussed  in Notes 1 and 4 and (ii) the  adoption of Financial
Accounting  Standards Board  Interpretation  No. 47, "Accounting for Conditional
Asset  Retirement  Obligations"  discussed  in  Notes 1 and 7) and  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, 2006.



/s/DELOITTE & TOUCHE LLP
New York, New York
February 22, 2007