Cabinet ministers and members of the National Security Council were told nothing about the British spy agency GCHQ's Tempora programme or the US National Security Agency's Prism surveillance programme, according to former government minister Chris Huhne.
Huhne, who was appointed secretary of state for energy and climate change in the coalition government in 2010, was part of the Cabinet until February 2012.
In his column for The Guardian, he claims that people would be shocked by what ministers don't know, and are not told.
"When it comes to the secret world of GCHQ and the US NSA, the depth of my ‘privileged information' has been dwarfed by the information provided by Edward Snowden," he said.
Huhne was part of the National Security Council, which was attended by ministers, heads of the secret and security services, GCHQ and the military, but he said that at no point was there any mention of Prism or Tempora.
The former government minister said he was shocked and mystified by Snowden's revelations.
"The state should not feel itself entitled to know, see and memorise everything that the private citizen communicates. We cannot even rely on incompetence as a bulwark for our freedoms. The state increasingly has the capability to retain everything as the cost of computer memory collapses," he said.
Huhne added that he was most mystified about the Home Office's attempts to persuade politicians to buy into the idea of enabling the UK to recover email and phone communication data - most recently via the Communications Data Bill - when it seems GCHQ is already tapping into this data. He questioned whether this was just a diversion tactic by the Home Office.
He offered several possible explanations as to why the Home Office would press forward with the Communications Data Bill anyway.
One reason, he said, could be that GCHQ may not be as confident as it claims about the legality of what it has been doing, while another reason could be that it never had the capability that Snowden's leaks claim.
"Maybe GCHQ is not as capable as its now-leaked boasts claim: every public body has a budget to protect. Maybe the securicrats thought that £1.8bn [the price set for the Communications Data Bill] was a modest price to duplicate what they were already doing," he suggested.
Huhne went on to suggest that even though it is only metadata that is being captured - the time and dates of calls for example - the sign-off to receive a warrant to get access to such data is far too easy, with half a million approvals by police inspectors every year.
"The sign-off should be tougher. After all, information that someone is calling Alcoholics Anonymous or the Samaritans may be embarrassing and damaging, although neither illegal nor suspicious," he said.
"Information is power, and the necessary corollary is that privacy is freedom. If GCHQ cannot keep its own secrets, what price keeping yours or mine?" he asked.
Huhne concluded that the Snowden revelations put a "giant question mark into the middle of our surveillance state" and that it was time that "our elected representatives insisted on some answers before destroying the values we protect".
Huhne was imprisoned for eight months for perverting the course of justice in March 2013.