Deputy prime minister Nick Clegg has said that plans to monitor the British public's web and email communications will be published in draft first so that they can be debated in Parliament.
Clegg told the BBC that the mass surveillance policy, which Home Secretary Theresa May had earlier said should be enacted as soon as possible, would not undermine people's civil rights.
"Any measures will be proportionate. They will not sacrifice people's civil liberties, we will not create a new government database and we will not give police new powers to look into people's emails," he said.
The Home Office has released a fact sheet about the communications data legislation, which says that police and security agencies can get access to communications data if they can demonstrate that it is necessary in a criminal investigation.
It adds that this communications data does not include the content of any communication, such as the text of an email or a conversation on the phone, only information about the communication itself.
Clegg said that there would be safeguards for privacy and civil liberties and suggested that the government would not push through the legislation without a "legitimate debate".
Liberal Democrat MPs and civil rights campaigners are opposed to the government being able to access the public's real-time communication information such as phone calls and emails.
In an open letter published in The Guardian, 16 Liberal Democrats backed the deputy prime minister's plans to publish draft legislation.
"Following worrying reports of possible government proposals to collect real-time information on people's activity online, including from social media sites, we were pleased to hear the deputy prime minister making clear his commitment to civil liberties and protecting privacy," the letter says.
Yesterday, The Equality and Human Rights Commission said that the plans would "potentially be incompatible with the right to privacy of many ordinary people in the UK".
Niri Shan from law firm Taylor Wessing also suggested that citizen's rights of privacy would be affected and that the legislation could be challenged under EU law.
"We have strong privacy protection in this country emanating from Article 8 of the European Convention on Human Rights. I believe what they are proposing would amount to a flagrant infringement of the citizen's right of privacy and I don't believe there is a public interest justification for it (which is the legal test to override someone's privacy).
"If they introduce such a law I believe it would be open to challenge on a European level under Human Rights legislation," he said.
Yesterday, a spokesperson for the data protection and privacy watchdog the Information Commissioner's Office (ICO) said that the criticism over the plans was a concern, but said that no official comment could be made unless the plans were formally announced.