This is a fork in the road

Can you fight terror with justice? Tomorrow the Commons will vote on the annual extension of control orders, under which terror suspects are subject to a range of measures from tagging to virtual house arrest. The government may seek to portray this as simply an administrative vote. In truth, it marks a fork in the road in the debate on how to tackle terrorism.Those of us who reluctantly accepted the introduction of control orders in emergency legislation two years ago did so following assurances that they were a temporary measure, introduced in response to the ruling that the detention of foreign nationals without trial was illegal. The government promised to review the orders, and replace or improve them after 12 months. In the wake of the bombings on July 7 2005, we accepted that an extra year would be needed to complete that review.

Control orders are unique in that they give a politician, rather than a judge, the power to curtail someone's freedom without even giving the individual the reasons why. They have also proved messy to implement in practice, as the ability of three suspects to escape their control orders showed. Even the home secretary, John Reid, admits they are "full of holes". And yet, the government seems to have abandoned all plans to review or replace them. This is, in large part, because the government appears to believe that our court system is not equipped to deal with the complexities of the contemporary terrorist threat.

It is true that the nature of modern terrorism poses huge challenges to our criminal justice system. But our response should be to reform, streamline and strengthen our system to bring terror suspects before court, rather than circumvent due process altogether. A battery of curfews and tags, imposed in a legal limbo at the behest of politicians, is no surrogate for the aggressive use of the full force of the law. Would-be terrorists are criminals, and should be treated as such.

I and my Liberal Democrat colleagues will be voting against the extension of control orders tomorrow because we believe more can and should be done to pursue prosecutions against terror suspects. Control orders should be repealed and replaced by a package of new measures to strengthen our ability to prosecute terror suspects in court.

Instead of holding suspects for extended periods without charge, we need to consider ways in which charges could be brought more rapidly in the first place. We should make it easier, for instance, for prosecutors to bring charges against terror suspects where evidence has not yet been fully produced but there is a good prospect that it will. We should also re-examine the circumstances in which the police can question suspects after charge.

A way to introduce phone-tap evidence in court must be found, with protections for the security services so agents and surveillance methods are not compromised. And we should use plea-bargaining more actively to encourage so-called supergrasses to give evidence against more serious criminals. The government has already passed plea-bargaining legislation to tackle organised crime: why not use it to thwart terror plots too?

If there remain a handful of individuals who cannot be charged, for whom control-order-like powers are still required, they must be granted by a judge, be time-limited, and be subject to a higher standard of proof and to regular and thorough assessments of the possibility of prosecution. Anything less is a betrayal not only of our traditional British system of justice, but also of our duty to pursue prosecutions against those criminals who plot to carry out terrorist atrocities.

Nick Clegg, the Liberal Democrat home affairs spokesman.