EXHIBIT 12.2
  1.
    
    I have reviewed this annual report on Form 20-F of National Grid plc;2.
    
    Based on my knowledge, this report does not contain any untrue statement of
a material fact or omit to state a material fact necessary to make the
statements made, in light of the circumstances under which such statements
were made, not misleading with respect to the period covered by this
report;3.
    
    Based on my knowledge, the financial statements, and other financial
information included in this report, fairly present in all material
respects the financial condition, results of operations and cash flows of
the company as of, and for, the periods presented in this report;4.
    
    The companys other certifying officer and I are responsible for
establishing and maintaining disclosure controls and procedures (as defined
in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over
financial reporting ( as defined in Exchange Act Rules 13a-15(f) and 15(d)
-15(f)) for the company and have:
 (a)
    
    Designed such disclosure controls
and procedures, or caused such
disclosure controls and procedures
to be designed under our
supervision, to ensure that
material information relating to
the company, including its
consolidated subsidiaries, is made
known to us by others within those
entities, particularly during the
period in which this report is
being prepared;(b)
    
    Designed such internal control
over financial reporting or caused
such internal control over
financial reporting to be designed
under our supervision, to provide
reasonable assurance regarding
reliability of financial reporting
and the preparation of financial
statements for external purposes
in accordance with generally
accepted accounting principles;(c)
    
    Evaluated the effectiveness of the
companys disclosure controls and
procedures and presented in this
report our conclusions about the
effectiveness of the disclosure
controls and procedures, as of the
end of the period covered by this
report based on such evaluation;
and(d)
    
    Disclosed in this report any
change in the companys internal
control over financial reporting
that occurred during the period
covered by the annual report that
has materially affected, or is
reasonably likely to materially
affect, the companys internal
control over financial reporting;
and
 5.
    
    The companys other certifying officer and I have disclosed, based on our
most recent evaluation of internal control over financial reporting, to the
companys auditors and the audit committee of the companys board of
directors (or persons performing the equivalent functions):
 (a)
    
    All significant deficiencies and
material weaknesses in the design
or operation of internal control
over financial reporting which are
reasonably likely to adversely
affect the companys ability to
record, process, summarize and
report financial information; and(b)
    
    Any fraud, whether or not
material, that involves management
or other employees who have a
significant role in the companys
internal control over financial
reporting.
 June 17, 2008
    
    /s/ Steve LucasSteve LucasTitle: Finance DirectorNational Grid plc