Exhibit 5-1

James T. Foran                Public Service Electric and Gas Company
General Corporate Counsel     80 Park Plaza, TSB, P.O. Box 570, Newark, NJ 07101
                              tel: 973.430.6131 fax: 973.642.5033
                              email: jforan@pseg.com

                                                                    [LOGO] PSE&G

                                                      December 27, 2001

Public Service Electric and Gas Company
80 Park Plaza
P.O. Box 570
Newark, NJ 07101-0570

            Re:   $1,000,000,000  aggregate  principal  amount  of  Senior  Debt
                  Securities (the "Senior Debt  Securities") to be issued in one
                  or more series by Public Service Electric and Gas Company (the
                  "Company")  and/or Trust Preferred  Securities (the "Preferred
                  Securities")  to be  issued  in one or more  series  by  PSE&G
                  Capital Trust III and PSE&G  Capital  Trust IV (the  "Trusts")
                  and Guarantees  with respect to the Preferred  Securities (the
                  "Guarantees") and Deferrable Interest Subordinated  Debentures
                  (the  "Subordinated  Debentures")  to be issued in one or more
                  series by the Company.

Ladies and Gentlemen:

      I am General  Corporate  Counsel of the Company and, in that  capacity,  I
have represented the Company in connection with the proposed issuance, from time
to time,  by the  Trusts  of the  Preferred  Securities  and the  execution  and
delivery by the Company of the Senior Debt  Securities,  the  Guarantees and the
Subordinated  Debentures.  The Senior Debt  Securities  will be issued  under an
indenture,  dated as of December 1, 2000 (as supplemented from time to time, the
"2000 Indenture")  between the Company and First Union National Bank as Trustee.
The  Subordinated  Debentures will be issued under an indenture (as supplemented
from time to time, the  "Indenture")  to be entered into between the Company and
the Trustee.  All capitalized terms used herein unless defined herein shall have
the meanings specified in the Registration Statement hereinafter described.

      I and/or  attorneys  working  under my  supervision  have  conducted  such
investigations of laws and regulations as I have deemed necessary or appropriate
for the purpose of rendering the opinions hereinafter expressed.

      The opinions expressed below are based on the following assumptions:

            (a) Each of the  Trusts  have  been  duly  created  and are  validly
      existing under the laws of the State of Delaware;

            (b) The  Registration  Statement  on  Form  S-3  (the  "Registration
      Statement") filed by the Company and the Trusts with respect to the Senior
      Debt  Securities,   the  Preferred  Securities,  the  Guarantees  and  the
      Subordinated Debentures will become effective;

            (c)  The  proposed  transactions  contemplated  by the  Registration
      Statement  will be  carried  out on the  basis set  forth  therein  and in
      conformity  with the  authorizations,  approvals,  consents or  exemptions
      under the securities laws of various states and other jurisdictions of the
      United States;

            (d) Prior to the  issuance of any series of Senior Debt  Securities,
      the Board of Directors of the Company (the "Board"),  a committee  thereof
      or the Sale and Pricing Committee of the Company  ("Committee"),  pursuant
      to delegated  authority from the Board,  will have authorized the issuance
      of, and established the terms of such series of Senior Debt Securities.

            (e) Prior to the  issuance  of any series of  Preferred  Securities,
      Guarantees and Subordinated Debentures:

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            (i) the  depositor of the Trust will  authorize the issuance of, and
      determine the terms of, such series of Preferred Securities;

            (ii) the  Indenture  will have been  executed  and  delivered by the
      Company, and the Board, a committee thereof or the Committee,  pursuant to
      delegated  authority from the Board, will have authorized the issuance of,
      and  established  the terms of the series of the  Subordinated  Debentures
      related to such series of Preferred Securities; and

            (iii) the Guarantee  related to such series of Preferred  Securities
      will have been executed and  delivered by the Company in  accordance  with
      appropriate  resolutions  of the  Board of  Directors  of the  Company,  a
      committee thereof or the Committee pursuant to such delegated authority.

            (f) The Indentures and the Guarantees  will each have been qualified
      in accordance  with the provisions of the Trust  Indenture Act of 1939, as
      amended.

      Based upon the foregoing and subject to the  limitations  herein,  I am of
the opinion that:

            1. The Company is a corporation  duly organized and validly existing
      and  authorized to exercise its corporate  powers,  rights and  privileges
      under the laws of the State of New Jersey.

            2. When properly  executed,  authenticated and delivered as provided
      in the 2001 Indenture,  the Senior Debt Securities will be legally issued,
      valid and binding obligations of the Company.

            3. When properly executed, authenticated,  delivered and paid for as
      provided in the Indenture,  the  Subordinated  Debentures  will be legally
      issued, valid and binding obligations of the Company.

            4.  When  properly  executed  and  delivered  by  the  Company,  the
      Guarantees will be valid and binding obligations of the Company.

      I express no opinions as to matters of law in jurisdictions other then the
State of New Jersey.  My opinions are rendered  only with respect to the laws of
the State of New Jersey and rules,  regulations and orders  thereunder which are
currently in effect.

      This opinion does not cover the necessity of filings under the  provisions
of  securities  laws of any  state in  which  the  Senior  Debt  Securities  and
Preferred Securities may be sold.

      The  opinions  set forth  above are  subject,  as to  enforcement,  to (i)
bankruptcy,  insolvency  (including,  without  limitation,  all laws relating to
fraudulent transfers), reorganization, moratorium or other similar laws relating
to or affecting the enforcement of creditors'  rights generally and (ii) general
equitable  principles  (regardless  of whether  enforcement  is  considered in a
proceeding in equity or at law).

      I  hereby  consent  to the  use of  this  opinion  as  Exhibit  5.1 to the
Registration  Statement and to the references to me under the heading  "Experts"
in the Prospectus and Prospectus Supplement contained therein.

                                       Very truly yours,

                                       /s/ JAMES T. FORAN
                                       ---------------------------------
                                       James T. Foran
                                       Associate Corporate Counsel