Crawley, UK--(Marketwire - June 1, 2007) -

                       SPIRENT COMMUNICATIONS PLC


London, UK - 1 June 2007: Spirent Communications plc ("the Company") (LSE: SPT;
NYSE: SPM), a leading communications technology company would like to notify the
market in accordance with the Financial Services Authority ("FSA") Disclosure
and Transparency Rules' ongoing disclosure requirements for issuers, of the
following information as at 31 May 2007:

The Company's issued share capital consisted of 959,329,216 ordinary shares of 3
& 1/3 pence with voting rights.  The Company held 76,745,000 ordinary shares in
Treasury, and the Company is not permitted to exercise voting rights in respect
of those ordinary shares.  Therefore, the total number of voting rights in the
Company was 882,584,216.

The above figure (882,584,216) may be used by shareholders as the denominator
for the calculations by which they will determine if they are required to notify
their interest in, or a change to their interest in, the Company under the FSA's
Disclosure and Transparency Rules.

                                    - ends -


Michael Anscombe          Spirent Communications plc          +44 (0)1293 767672
Deputy Company Secretary

About Spirent Communications plc

Spirent Communications plc is a leading communications technology company
focused on delivering innovative systems and services to meet the needs of
customers worldwide.  We are a global provider of performance analysis and
service assurance solutions that enable the development and deployment of
next-generation networking technologies such as broadband services, Internet
telephony, 3G wireless and web applications and security testing.  The Systems
group develops power control systems for specialist electrical vehicles in the
mobility and industrial markets.  Further information about Spirent
Communications plc can be found at

Spirent Communications plc Ordinary shares are traded on the London Stock
Exchange (ticker: SPT) and on the New York Stock Exchange (ticker: SPM; CUSIP
number: 84856M209) in the form of American Depositary Shares ("ADS"),
represented by American Depositary Receipts, with one ADS representing four
Ordinary shares.

Spirent and the Spirent logo are trademarks or registered trademarks of Spirent
Communications plc.  All other trademarks or registered trademarks mentioned
herein are held by their respective companies.  All rights reserved.

This press release may contain forward-looking statements (as that term is
defined in the United States Private Securities Litigation Reform Act of 1995)
based on current expectations or beliefs, as well as assumptions about future
events.  You can sometimes, but not always, identify these statements by the use
of a date in the future or such words as "will", "anticipate", "estimate",
"expect", "project", "intend", "plan", "should", "may", "assume" and other
similar words.  By their nature, forward-looking statements are inherently
predictive and speculative and involve risk and uncertainty because they relate
to events and depend on circumstances that will occur in the future.  You should
not place undue reliance on these forward-looking statements, which are not a
guarantee of future performance and are subject to factors that could cause our
actual results to differ materially from those expressed or implied by these
statements.  The Company undertakes no obligation to update any forward-looking
statements contained in this press release, whether as a result of new
information, future events or otherwise.

                      This information is provided by RNS
            The company news service from the London Stock Exchange