(LOGO)
                                                P.B.P. Bevan
                                                Group General Counsel
                                                BP Legal

                                                BP p.l.c.
                                                Britannic House,
                                                1 Finsbury Circus,
                                                London EC2M 7BA

                                                Switchboard:  020-7496 4000
                                                Central Fax:  020-7496-4630
                                                Telex:  888811

                                                Direct Line:  020-7496 4013
                                                Direct Fax:  020-7496 4592



                                                          EXHIBIT 5(a) and 23(b)

                                        July 31, 2001

The Directors,
BP p.l.c.,
Britannic House,
1 Finsbury Circus,
London EC2M 7BA.

Dear Sirs:

Registration Statement on Form S-8 (the "Registration Statement")

1.   This opinion is given in connection with the registration  under the United
     States  Securities Act of 1933, as amended,  of US $110,000,000 of deferred
     compensation  obligations (the "Deferred  Compensation  Obligations") of BP
     p.l.c.,  an English public limited  company  formerly named BP Amoco p.l.c.
     (the "Company"), to be offered under the BP Deferred Compensation Plan (the
     "Plan").

2.   This opinion is limited to English law as applied by the English courts and
     is given on the  basis  that it will be  governed  by and be  construed  in
     accordance  with  English  law.

3.   I have  examined and relied on copies of such  corporate  records and other
     documents,  including the  Registration  Statement,  reviewed the corporate
     proceedings  in connection  with  adoption and  amendment of the Plan,  and
     reviewed such matters of law as I have deemed  necessary or appropriate for
     the purpose of this opinion.

4.   On the basis of, and subject to, the  foregoing  and having  regard to such
     considerations  of  English  law in force at the date of this  letter  as I
     consider  relevant,  I am of the  opinion  that the  Deferred  Compensation
     Obligations  have been duly  authorized for issuance and, when the Deferred
     Compensation Obligations are issued by the Company pursuant to the terms of
     the Plan, will be valid and binding obligations of the Company, enforceable
     against  the  Company in  accordance  with their terms and the terms of the
     Plan,  except  as   enforceability   (i)  may  be  limited  by  bankruptcy,
     insolvency,  reorganization  or other  similar  laws  affecting  creditors'
     rights  generally  and (ii) is  subject  to  general  principles  of equity
     (regardless of whether such enforceability is considered in a proceeding in
     equity or at law).

I consent  to the  filing of this  opinion  as an  exhibit  to the  Registration
Statement.  In giving such  consent I do not admit that I am in the  category of
persons whose consent is required under Section 7 of the Securities Act of 1933,
as amended.

                                        Yours faithfully,

                                        /s/ Peter B. Pugh Bevan
                                        P.B.P. Bevan