Director/PDMR Shareholding

National Grid PLC
25 August 2006

National Grid plc ('NG')
25 August 2006

Notification of Directors' Interests:

The Trustee of the National Grid USA Incentive Thrift Plan ('Thrift Plan')
notified NG today that, following the reinvestment of the 2005/06 final dividend
of $992.06, Mike Jesanis became interested in an additional 16.3559 ADSs (held
in the Thrift Plan) purchased at $60.6546 per ADS on 23 August 2006.

NG yesterday received notification that following the operation of the NG
Dividend Reinvestment Plan (DRIP), Sir John Parker became interested in an
additional 102 ordinary shares purchased at £6.35 per share on 23 August 2006.

NG yesterday received notification that, following the operation of dividend
reinvestment as part of the Lattice Group All Employee Share Ownership Plan,
Steve Lucas became interested in an additional 21 ordinary shares purchased at
£6.365 per share on 23 August 2006.

Notification of Directors' Technical Interests, Pursuant to Section 324(2) of
the Companies Act 1985:

NG yesterday received a notification from Towers Perrin Share Plan Services
(Guernsey) Limited , as Trustee of both the National Grid Group Employee Share
Trust and The National Grid plc 1996 Employee Benefit Trust (holding shares in
conjunction with the Share Matching Plan), that following the purchases set out
below Roger Urwin, Steve Holliday, Steve Lucas, Nick Winser and Edward Astle are
deemed to have a technical interest in the new balances as stated:


Trust                 Shares purchased     Price                Date Purchased       Balance of shares
                                                                                     held in trust

National Grid Group   400                  £6.365               23/8/06              201,374
Employee Share Trust

The National Grid plc 84                   £6.365               23/8/06              57,369
1996 Employee Benefit
Trust



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