MI5 and the police will be able to sift through mobile phone and internet data under emergency laws being rushed through Parliament, David Cameron has announced.
The Prime Minister said the measures were needed to “maintain powers to help keep us safe from those who would harm UK citizens.”
He and the Deputy Prime Minister will hold a rare joint press conference later on Thursday to outline the plans.
IT comes after Home Secretary Theresa May struck a deal with Nick Clegg who previously resisted efforts to pass the so-called “snooper’s charter”.
Phone companies and internet firms will be required to store data for 12 months, under the plans.
The Government was forced to act after the European Court of Justice (ECJ) ruled that a European Union data retention directive, which was implemented by Labour in 2009, was invalid.
It is understood the powers will be limited to just high counter-terrorism operations and the detecting of very serious crime.
The compromise has been reached as fears grow of the terrorist threat posed by Britons who have been radicalised by groups fighting in Syria and Iraq returning to the UK.
The proposals were discussed at an emergency meeting of the Cabinet on Thursday morning.
Earlier this week Mrs May suggested that Britain’s child sex abuse investigation body needs more access to phone and internet records so it can better investigate crimes.
She said the Child Exploitation and Online Protection Centre (Ceop) needed to continue to have access to communications data.