The Woolwich murder will be used by Theresa May, the Home Secretary, to revive plans for a “snoopers’ charter” allowing the police and the security services to monitor internet use, Conservative sources indicated.
Mrs May was furious when Nick Clegg, the Deputy Prime Minister, vetoed the inclusion of the contentious scheme in this month’s Queen’s Speech on the grounds that it was disproportionate and an invasion of privacy.
She faces demands from senior figures in all parties to strengthen police and security service powers following Wednesday’s killing of an off-duty soldier.
David Cameron and Tory ministers insisted they would not rush into “knee-jerk” legislation while feelings were running high, but are now preparing to return to the scheme before the next election.
The move would provoke a fierce Coalition row as the Liberal Democrats are strongly opposed to the planned Communications Data Bill, which is currently on ice.
A senior Tory told The Independent: “The Home Secretary is very keen to do something shortly that includes at least some of this Bill.
“I suspect any opportunity to strengthen pressure on the naysayers will be taken. She is absolutely determined to do something on this.”
Under Mrs May’s plans, internet service providers would be required to store data about website visits, emails, mobile calls and messages on social media and Skype.
The information would cover the time, duration and recipient of messages, but not their contents.
The Home Secretary insisted the moves would help to monitor terrorists who were turning to sophisticated technology to escape detection.
A Home Office source said: “It’s a simple idea about giving the authorities the tools to keep track of pretty clever people. When people understand what’s being proposed, it’s hard to object.”
Security sources acknowledged it was unclear whether the Bill’s proposed powers would have thwarted the Woolwich attack and signalled their wariness over being used for “political purposes”.
But they said that greater access to contacts between terror suspects would be useful in the early stages of an investigation and to collect evidence to secure a conviction.
Senior Conservatives insist that talks are continuing within the Coalition over the Bill’s fate and that Liberal Democrat objections can be overcome.
But a spokesman for Mr Clegg said: “There are already substantial powers in place to track the communications of criminals and terrorists.”
And a Liberal Democrat source warned the Deputy Prime Minister would face “open revolt” from his party’s grassroots if the Bill was revived.
Calls for the extension of email and internet monitoring powers were led by Lord Carlile, the former independent reviewer of terror laws, who is a Liberal Democrat peer.
He said the Woolwich attack should give the Government “pause for thought” over its decision to shelve the Bill.
He also suggested ministers should look afresh at its move to replace control orders for terror suspects with the “diluted” system of Terrorism Prevention and Investigation Measures (Tpims).
“We must ensure the police and the security services have for the future the tools they need which will enable them to prevent this kind of attack taking place,” Lord Carlile said.
Lord Reid, the former Home Secretary, said mobile phone data had been crucial in saving 2,500 lives by foiling a plot in 2006 to blow up airliners using liquid explosives.
But he added: “Now people have moved on from mobile phones to internet, email, text, Skype. We don't have the means of doing what we did six years ago.”
Nick Pickles, director of the civil liberties campaign group Big Brother Watch, warned of the “dangers of rushing forward policy changes when the nation is in shock and of those who seek to use the politics of fear”.
Mr Cameron said: “After an event like this, it is natural questions will be asked about what additional steps can be taken to keep us safe. I will make sure those questions are asked and answered. But I am not in favour of knee-jerk responses.”