"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. We need to take action to maintain the continued availability of communications data as technology changes," a spokesman said.

"Communications data includes time, duration and dialling numbers of a phone call, or an email address. It does not include the content of any phone call or email and it is not the intention of Government to make changes to the existing legal basis for the interception of communications."

Nick Pickles, director of the Big Brother Watch campaign group, said: "This is an unprecedented step that will see Britain adopt the same kind of surveillance seen in China and Iran.

"This is an absolute attack on privacy online and it is far from clear this will actually improve public safety, while adding significant costs to internet businesses.

"If this was such a serious security issue why has the Home Office not ensured these powers were in place before the Olympics?"

Shami Chakrabarti, director of the civil rights group Liberty, said that both the Conservatives and the Liberal Democrats had resisted the plan when they were in opposition.

"There is an element of whoever you vote for the empire strikes back," she told Sky News's Murnaghan programme.

"This is more ambitious than anything that has been done before. It is a pretty drastic step in a democracy.

"It was resisted under the last government. The coalition bound itself together in the language of civil liberties. Do they still mean it?"

Conservative backbencher Margot James said ministers would come under pressure to water down the proposals as the legislation passed through Parliament.

"I am sure there will be considerable pressure brought to bear as the proposals are debated for protections to be built in to protect people's privacy," she told the Murnaghan programme.