Charles Kennedy: There are limits to our co-operation over terror

People may be suspicious of matey comings and goings in Downing Street

Just after the 7 July bombs, I caught the Tube to Westminster. It wasn't a publicity stunt - it was the quickest way to get there. I must admit, I glanced around at my fellow passengers rather more carefully than usual. A little to my surprise, many smiled back and a couple shook my hand. It was a case of being "all in it together" - and I spent the rest of the journey musing on the need to reassure people that politicians are on their side at key moments.

Given the current cynicism about politicians and their motives, I reached an early conclusion that this was a moment to demonstrate that we can work together and that my party would go out of its way to avoid party point-scoring in the aftermath of these events. In fact, I suggested to the Prime Minister soon after 7 July that the leaders of the three major parties should all meet with representatives of the Muslim community; an idea which resulted in a very positive encounter.

The first job of government, obviously, is to ensure the safety of its citizens. Like everyone else, I want the police to catch whoever carried out those warped and despicable acts. But I recognise that people may also be inherently queasy or suspicious of apparently matey cross-party comings and goings from Downing Street. It is certainly unusual, and for those who believe that opposition politicians are elected to oppose, let me offer some reassurance.

As leader of the Liberal Democrats - a party with civil liberties at the heart of its thinking - there is no question of compromising our principles. It is precisely when there is some kind of emergency that governments, the police and security services are tempted to reach for extra powers at the expense of the rights of the individual citizen. During our Downing Street encounters, I have made it clear to the Prime Minister that our party is content to work with him to ensure that everyone can go about their business in safety, but we will oppose any measure which is not proportionate to the immediate threat.

Yet I am also keen not to repeat the recent fractious debate over control orders. That took place just before the general election, against a background of insults, briefings and spin about who was being "soft on terror". The resulting legislation was rushed and flawed. But it should also be recognised that, at the end of a long and bruising argument, my party acknowledged that there was a gap in the law dealing with terrorist suspects which needed to be filled. We secured much-needed improvements to the legislation, for example the commitment that a judge, not a politician, would impose control orders, as well as a commitment that the principles would be revisited and the Act replaced as soon as possible.

The nub of the current cross-party discussions is fresh legislation dealing directly with issues arising from the recent bombings. In a minor turning of the tables, we Liberal Democrats and Tories are urging the Government to accept the use of evidence in court gained through intercepting phone calls or e-mails. Such a change in the law has been supported by two parliamentary committees, but is resisted by the security services.

We also welcome the proposals to plug existing loopholes concerning "acts preparatory to terrorism". Such law would require evidence of an intention to commit a terrorist act, such as attending a foreign terrorist training camp - an approach we have advocated for some time.

Where there is a need for greater discussion and further meetings later in the summer is over proposals to widen admissible questioning of suspects outside the context of their arrest, and the suggestion that detention of suspects should be extended from 14 days to three months. The problem is you could end up reintroducing detention without trial (Belmarsh style) by the back door. A second risk is that it could encourage "lazy" policing, with officers making arrests on little or no evidence, safe in the knowledge that they can continue their investigations at leisure. If, after three months, no charges are brought, that would mean that an innocent person had in effect served a six-month prison sentence (since a six-month term includes three months remission), having never been near a court. There are real dangers here.

Unquestionably, these are unsettling times. The London Tube bombings have brought a new context to our national life, and no one can afford to be complacent. Yet we must never give the terrorists a chance to claim a success. It is therefore incumbent on all of us in Parliament to find the right balance between the conflicting demands of security and individual freedom.

The writer is leader of the Liberal Democrat Party