A landmark legal battle against mass government snooping is being played out in the High Court today as two backbench MPs use the The Human Rights Act (HRA) to fight emergency surveillance powers that were fast-tracked through Parliament last year.
Backed by the campaign group Liberty, Conservative former shadow home secretary David Davis and Labour deputy leadership candidate Tom Watson have brought a judicial review that centres on the Data Retention and Investigatory Powers Act (Dripa).
Dripa was rushed through Parliament in just three days in July with the backing of all three major party leaders.
The challenge from Davis and Watson was facilitated by the HRA, which the Conservative government has pledged to abolish and replace with a "bill of rights".
The MPs are seeking a ruling from the court that Dripa is not compatible with Article 8 of the European Convention on Human Rights (ECHR), which guarantees the right to a private life.
The HRA incorporates the ECHR into British law, enabling the MPs to bring the legal challenge before an English court.
Emma Norton, legal officer for Liberty, said: "It is thanks to the HRA that we are able to challenge the government's actions.
"The same government which now seeks to axe that very piece of legislation and, by doing so, curb the British people's ability to do so in future."
Watson said: "The government's decision to use emergency powers to enable it to spy on citizens shows the rights of the individual need to be strengthened to ensure the state can't act with impunity.
"Even MPs are powerless to prevent such powers being enacted.
"The Human Rights Act allows us to challenge those powers in the courts but the Tory Government is intent on tearing up the Act and doing away with the limited legal protection it affords.
"It is vital that we fight for it to be retained."
In December, Mr Justice Lewis, gave them permission to bring the case. A full hearing will now take place this week before Lord Justice Bean and Mr Justice Collins.
The judges will hear argument that Dripa is incompatible with the ECHR and the EU Charter of Fundamental Rights relating to respect for private and family life and protection of personal data.
Last year, David Cameron and the then Deputy Prime Minister Nick Clegg said the accelerated passage of Dripa through Parliament was necessary because of an emergency created by a ruling in April last year by the European Court of Justice, which they said would have the effect of denying police and security services access to vital data about phone and email communications.
They insisted Dripa would simply maintain existing powers, which required communications companies to retain data for 12 months for possible investigation, but did not allow police or security agencies to access the content of calls or emails without a warrant.
Norton added: "The executive dominance of Parliament in rushing through this legislation - using a wholly fabricated 'emergency' - made a mockery of parliamentary sovereignty and the rule of law, and showed a staggering disregard for the entire population's right to privacy."
Liberty says it does not dispute the role of communications data in solving and preventing crime, "but does not believe that justifies the costly and lengthy mass retention of records of those who are not involved in such investigations".
It is calling for prior judicial authorisation and a requirement that data is only retained as part of investigations into serious crime and to prevent death and injury.
Speaking to HuffPost UK earlier this year, Davis said the politicians' understanding of the internet and peoples' digital rights was akin to "the reaction of a Stone Age man to the combustion engine".
Describing his pending legal challenge to Dripa, he said the government "lied" about its surveillance, which, he added, became evident after a decision by the Investigatory Powers Tribunal which found GCHQ contravened the European Convention of Human Rights in its scheme for sharing intelligence with the American NSA.
“And we have tended to believe the state in the past. You don’t like to think GCHQ are lying,” he said.
He was interviewed as part of HuffPost UK's 'Digital Deficit' series, which looked at politicians' digital illiteracy and its impact on their law-making.