Home Office ministers are to press ahead with their campaign to give the police and security services sweeping "snooper's charter" powers to monitor internet and phone use in Britain despite the outcry over the disclosure of the scale of US internet surveillance.

"It does not change our position. The government is continuing to look at ways of addressing this issue with communication service providers. This may involve legislation," said a Home Office source.

But the disclosures have reinforced the resolve of those opposed to the home secretary's communications data bill, which has so far been blocked by the Liberal Democrats, who say it represents a stark warning of what could happen under any new British web monitoring legislation.

Julian Huppert, the Lib Dems backbench home affairs spokesman, said: "What we have learned from Prism is that it is even more important to have robust privacy safeguards in place if the home secretary tries to sneak something like this through Parliament. People don't think it is right for the government to have this broad access. The public are now far more aware of this. We are saying 'no', and we are continuing to say 'no'."

After Nick Clegg blocked the "snooper's charter" legislation from last month's Queen's Speech the cabinet secretary, Sir Jeremy Heywood, is trying to break the coalition deadlock by leading a Cabinet Office team to examine the scope there is, if any, to introduce sweeping new web and phone surveillance powers using existing legislation.

One option being considered is to use a 2006 European Union directive on data retention, which was introduced in the aftermath of the London attacks in July 2005, but was never fully implemented. This requires internet and phone companies to store for 12 months and hand over on request to the police and security services traffic data - the who, what, when and where of internet communication, that they already retain for billing and other business purposes. May's supporters argue that this could provide a "back door" solution to the coalition stalemate which would not require Lib Dem backing to get through Parliament.

But some security experts say that this may prove a limited option as it fails to capture the communications data for social media interactions, such as specialist chat rooms and Skype phone calls, that are no longer or never have been recorded for billing purposes. While some companies, such as EE, do retain and store the history of web use or weblog of users for up to 12 months, many others do not.

The EU directive is also limited in scope and would not be able to tackle the problem of overseas phone and internet companies, such as the American-based Google, Twitter, Yahoo, Microsoft, and Facebook, which are responsible for such a huge slice of web traffic. The "big five" have already written May a confidential letter warning that they are unlikely to co-operate voluntarily with her tracking proposals which they regard as "expensive and highly contentious".

The latest published figures show that public authorities, including the police and security services, already make half a million requests a year to the phone and internet companies for communications data in the course of their investigations. Their existing powers under the Regulation of Investigatory Powers Act 2000 give the police and security services the right to request for a named suspect to the "who, what, when and where'' of web and phone traffic data records that are already kept by the companies for their own business purposes.

The 2011 figure of 494,078 requests for communications data was 11% lower than the 2010 figure of 550,000. The 2011 figure of 494,078 requests for communications data was 11% lower than the 2010 figure of 550,000. Within that, however, there is no breakdown as to how many times the security services as opposed to the police sought such data. No separate ministerial authorisation or warrant was needed for law enforcement agencies to obtain this data which forms such an important part in modern investigations.

That came in addition to the 2,911 interception warrants that were signed in 2011 authorising the police or security services to listen in to the phone calls or read the content of emails and texts which were personally signed by the home secretary or scottish secretary. But the number of intercept warrants signed by the foreign, defence and Northern Ireland secretaries is not disclosed.

Sir Paul Kennedy, the Interception of Communications Commissioner, said the reduction in use of these powers was the result of the conclusion of a number of long-running investigations, where this data was pivotal, in 2010, a reduction in the number of major inquiries and budgetary restraints. While the overwhelming majority are for the use in terrorist and serious crime investigations a Freedom of Information request revealed that the Humberside police have made requests for this data to prosecute traffic offenders.