In a democracy there will always be a tension between security and privacy. Most people want the police and the security services to have the necessary powers to be able to deal effectively with serious crimes including murder, child sexual exploitation, terrorism and locating missing people. But equally, most people are very uncomfortable with the idea that the state should be able to access the records of every website they have ever visited. Getting the balance right matters for security, for privacy and for democracy.

The surveillance bill is as big a threat to state security as to personal liberty | Simon Jenkins Read more

The current surveillance framework is set in legislation passed in 2000. In the intervening 15 years, so much has changed. The landline and basic mobile phones have been replaced with any number of sophisticated devices and apps. Although it hardly seems possible, Facebook was only launched in 2004 and Twitter came two years later in 2006.

As a result, the case for reform is overwhelming. There should be no gaps in the ability of the police and security services when dealing with serious crime; no safe places where those intent on harming others can go about their business undisturbed. But just as the case for reform gets stronger, so does the case for effective safeguards. Extensions of surveillance can only be justified if accompanied by much improved transparency and ever more robust oversight and scrutiny.

Yesterday Theresa May, the home secretary, unveiled the government’s plans for reform by publishing a draft investigatory powers bill. Weighing in at 296 pages, the devil will obviously be in the detail. But we do know that there is a welcome “double lock” in the bill. This means that authorisation of the most intrusive investigatory powers, whereby intercept warrants are issued by the secretary of state, will not come into force until formally approved by a judge.

Judicial oversight adds a level of independent scrutiny previously lacking. Thousands of interception warrants are granted every year: more than 2,700 applications for warrants were considered and signed off last year by the home secretary, foreign secretary and Northern Ireland secretary. The sheer volume means that while the relevant secretary of state will consider each application, in reality a great deal of the preparatory work is routinely done by support staff. Although that arrangement may have worked well in the past, without judicial oversight it is not appropriate for the future.

The proposed involvement of judges will not reduce accountability as some have claimed. As the independent reviewer of terrorism, David Anderson QC, put it in his report to the home secretary, published in June this year: “The secretary of state is in practice rarely, if ever, held politically accountable for the issue of warrants.” Legislation prevents unauthorised disclosure of any detail about individual warrants, and intercepted material is not admissible in court. As far as I have been able to research, there has never been an occasion on which any secretary of state has ever been held politically accountable for the issue of individual warrants.

Mass snooping and more – the measures in Theresa May's bill Read more

But the case for judicial involvement does not end there. As surveillance powers are extended, the trust of all our communities in their exercise becomes increasingly important. In the aftermath of terrorist atrocities the inevitable calls from politicians for certain communities to take more responsibility for the actions of those assumed to be among their number who may have had an involvement can cause real damage to our social cohesion. Requiring decisions by politicians to be approved by judges in the most sensitive cases should help to restore trust in the system as a whole.

Clearly the draft investigatory powers bill now needs to be closely scrutinised before it begins its journey through both houses of parliament. Hard questions should focus on the test to be applied by judges before formally approving an intercept warrant; real judicial scrutiny is a safeguard, a judicial rubber stamp is not. And the detailed provisions for the retention and use of internet-connection records, which considerably extend the surveillance reach of the state, need careful attention: what are the limits on retention, and how closely defined and controlled will access to this material really be?

It will be for the government to answer these questions: but the bill is a step in the right direction.