The UK government could track all emails and phone calls made in the UK, if its plans for a vast centralized database go ahead.

The plans may be included in the draft Communications Data Bill, under which the government has proposed better policing of data, including that on IP networks, in the interests of national security.

The government said in a statement that it needed to keep up with changes in technology so that it could better track communication.

"We are at the very early stages of deciding how to update the law to allow public authorities to continue to obtain and have access to communications data essential for counter-terrorism and investigation of crime purposes," it said.

"Losing the ability to use this data would have very serious consequences for law enforcement and intelligence gathering in the UK."

Ministers have not yet made a decision on whether a central database will feature in the bill.

Jonathan Bamford, assistant Information Commissioner, said that if all the records were held on one database, it "may well be a step too far."

"We are not aware of any justification for the state to hold every UK citizen's phone and internet records. We have real doubts that such a measure can be justified, or is proportionate or desirable." Safeguards would need to be in place to govern who can access the data, he said.

He also raised questions over the security of the data: "Holding large collections of data is always risky; the more data that is collected and stored, the bigger the problem when the data is lost, traded or stolen."

Chris Huhne, Liberal Democrats home affairs spokesperson, called the plans "an Orwellian step too far", adding: "Given the appalling track record of data loss, this state is simply not to be trusted with such private information."

Shadow home secretary David Davis agreed: "Given [ministers'] appalling record at maintaining the integrity of databases holding people's sensitive data, this could well be more of a threat to our security than a support."

But while the government is moving to better track communications data, it once again missed an opportunity to express commitment to a dedicated e-crime unit when it launched the Communications Data Bill.

A proposal for a 50-strong, £5.3 million unit that would focus on investigating and fighting internet crime, was made last year but is still awaiting a response from the government.