David Cameron government's plans to enact legislation to allow officials to monitor phone calls, emails, texts and website visits of everyone in the UK have provoked a welter of protest amidst accusations of bringing in 'Big Brother'-style governance.
The Home Office believes that such powers are necessary to deal with crime and terrorism.
Opposition to the plans likely to be outlined in the Queen's Speech in May has come in from inside and outside the ruling coalition, including civil liberties groups.
If the plans are enshrined in law, Internet service providers will be required to give intelligence agency GCHQ access to communications in real time, which critics likened to state intrusion in China or Iran.
A 10 Downing Street spokesman said that data communication was used in 95 per cent of all serious crime and terrorism cases and "what we do need to make sure is that as technology changes we are able to maintain our current capability in this area".
Criticising the plan, senior Conservative leader David Davis said the plans will make existing surveillance legislation "60 million times worse". The new powers risked causing enormous resentment by allowing "unfettered" access to all forms of communication.
Deputy Prime Minister Nick Clegg said: "I am totally opposed to the idea of governments reading people's emails at will or creating a new central government database. The point is we are not doing any of that and I wouldn't allow us to do any of that".
He added: "All we are doing is updating the rules which currently apply to mobile telephone calls to allow the police and security services to go after terrorists and serious
criminals and updating that to apply to technology like Skype which is increasingly being used by people who want to make those calls and send those emails."
Under existing laws, Instead service providers have to keep details of users' internet access, email and internet phone calls for 12 months under an EU directive from 2009.
The content of the calls themselves is not kept, but details of the sender, recipient, time of communication and geographical location are recorded.
The proposed new law will reportedly allow GCHQ to access that data in real-time, rather than doing so retrospectively. In a statement, the Home Office said action was needed to "maintain the continued availability of communications data as technology changes.
It is vital that police and security services are able to obtain communications data in certain circumstances to investigate serious crime and terrorism and to protect the public."
A spokesman said: "As set out in the Strategic Defence and Security Review we will legislate as soon as parliamentary time allows to ensure that the use of communications data is compatible with the government's approach to civil liberties."
Shami Chakrabarti, director of campaign group Liberty, said: "This is more ambitious than anything that has been done before. It is a pretty drastic step in a democracy."
The Internet Service Providers Association said any change in the law must be "proportionate, respect freedom of expression and the privacy of users".
