The review has sparked intense discussions at GCHQ as intelligence services try to win resources and pitch desired reforms

Wider surveillance powers for the intelligence services to tackle terrorists, foreign spies and serious organised crime will be examined in the Whitehall defence review launched this year.

Ministers are set to consider whether to broaden the remit of surveillance warrants to extend their time limits and the scope of the operations they allow.

During the general election campaign, Boris Johnson pledged to launch the most profound review of Britain’s defence and security since the Cold War. The announcement sparked intense preliminary discussions in Whitehall departments, the armed forces, MI6, MI5 and GCHQ as they try to win resources and pitch desired modernisation reforms.

Security officials are understood to be concerned that the present system of sign-off may be hampering operational agility and effectiveness.

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