Communications firms will be legally required to help spies hack into suspects' smartphones and computers under a new snooping law unveiled today.
Domestic providers will be obliged to assist authorities in "giving effect to equipment interference" under the draft Investigatory Powers Bill.
This capability allows agencies to interfere with electronic equipment in order to obtain data such as communications from a device.
It can involve remote access to computers to covertly download the contents of a mobile phone during a search.
This is not a new power and a number of firms already assist in the activities voluntarily, officials said, but they will be legally obliged to provide assistance in future.
All police forces will be permitted to carry out equipment interference under the new regime, with a code of practice to be issued to regulate use of "more sensitive and intrusive techniques".
The bill also confirmed plans for:
:: The appointment of around seven High Court judges as judicial commissioners in a new "double lock" approval system for more intrusive capabilities such as interception operations in which agencies see the content of communications, bulk data collection and equipment interference.They will have the power to veto warrants signed by Secretaries of State.
:: A new requirement for internet firms to store records of people's web and social media use covering services they connect to but not their full browsing history or content of communication for up to a year. This would mean, for example, police can see someone has visited Google.co.uk, but not what searches they have made.
:: An overhaul of the oversight arrangements which will be headed by a new Investigatory Powers Commissioner, who will be a senior judge.
Home Secretary Theresa May said the publication of the bill is "a decisive moment".
She said: "Never before has so much information been in the public domain about the activities of our police and security services, as well as the oversight, safeguard and authorisation arrangements which govern them.
"I am clear we need to update our legislation to ensure it is modern, fit for purpose and can respond to emerging threats as technology advances.
"There should be no area of cyberspace which is a haven for those who seek to harm us to plot, poison minds and peddle hatred under the radar.
"But I am also clear that the exercise and scope of investigatory powers should be clearly set out and subject to stringent safeguards and robust oversight."
She argued that the bill will establish "world-leading oversight to govern an investigatory powers regime which is more open and transparent than anywhere else in the world".