If there's one thing we've learned since the Edward Snowden revelations, it's that the protection of our civil liberties requires constant vigilance. But in our digital world it is becoming harder to know when our fundamental human rights are being breached. From our location to our social connections and electronic conversations, the metadata of our nation is being collected, filtered and analysed.

Our intelligence and security services do an immensely challenging and thankless task: protecting us from organised crime, cyber threats and terrorist attacks. They will naturally want to use the best tools at their disposal, but this comes at a cost to privacy and civil liberties. Where we strike the balance between the two, and how we improve both of them, is supposed to be a matter for parliament. It is we parliamentarians who have approved the legislation and the policies, and who are supposed to carry out oversight of the intelligence and security services.

But parliament has failed to do this job. The legislative framework we have is woefully out of date and worryingly inadequate; parliament must do better. That is why we are proposing a digital bill of rights to enshrine proper protections for citizens. Last Tuesday Nick Clegg commissioned an independent body to review our legal framework for surveillance. The following day we hosted a debate with Alan Rusbridger – the editor-in-chief of this paper – MPs, peers, journalists and members of civil society on what this reform might look like. And this Sunday, at the Lib Dem spring conference, party members will get their say on a digital bill of rights. We plan for this to be a core part of our civil liberties case at the next election.

We are proud that the Lib Dems are leading the debate on this vital issue in parliament, just as it was us who killed off the communications data bill, which would have led to even more state surveillance. At its core, our proposal for a digital bill of rights ensures that there will be no surveillance without suspicion, and that our digital communication and behaviour will be treated with the same respect and legal due process that we expect for our offline communication and behaviour. We echo Clegg's call for the annual release of government transparency reports alongside a comprehensive review of all oversight committees, commissioners and tribunals.

This week Labour realised that the momentum for change was gathering pace and quietly improved its position on mass surveillance. We welcome its support for some key aspects of our policy – though we want the party to go much further. We will also continue to encourage the Tories to wake up to the concerns of so many public figures, journalists and civil liberties groups, not to mention vast swaths of the public. Not only is mass surveillance wrong in principle, it is ineffective in practice. We should not be wasting limited resources spying on innocent people.

As David Anderson QC, the independent reviewer of terrorism legislation, observed: "It is often said that the threat from terrorism is overestimated, and the resources devoted to countering it excessive." He added that the threat is sometimes "exaggerated for political or commercial purposes. It is certainly a powerful rallying cry for the flourishing security and surveillance industries." We agree. Fear and blanket claims of national security must not be allowed to stifle the debate around privacy and security.

The issue of privacy and civil liberties may not have had the attention it deserves in parliament, but our core liberal principles compel us to fight for these rights. As the Lib Dem constitution makes clear: "We will at all times defend the right to speak, write, worship, associate and vote freely, and we will protect the right of citizens to enjoy privacy in their own lives and homes." The UK has a proud history of leading on freedoms and civil liberties. Parliament should be leading the debate, not trailing it