The stealthy erosion of civil liberties that have been fought for over the centuries

Notwithstanding the Home Secretary's last-minute "concession" in the House of Commons yesterday, the case against the Government's Prevention of Terrorism Bill is overwhelming. If this Bill becomes law it will mean an individual can be detained, for an indefinite period, in his or her home. British citizens could be deprived of their liberty without knowing of what they are accused. Nor would they be allowed to challenge the evidence against them.

Notwithstanding the Home Secretary's last-minute "concession" in the House of Commons yesterday, the case against the Government's Prevention of Terrorism Bill is overwhelming. If this Bill becomes law it will mean an individual can be detained, for an indefinite period, in his or her home. British citizens could be deprived of their liberty without knowing of what they are accused. Nor would they be allowed to challenge the evidence against them.

This Bill would compromise one of our fundamental civil liberties - the right to a fair trial. This is the cornerstone of our freedom. For it to be suspended - however temporarily - the Government would have to show that our nation is facing an overwhelming threat and that it has absolutely no alternative course of action. It has failed to do either of these things.

Charles Clarke's claim that a High Court judge - rather than the Home Secretary - will be responsible for issuing house arrest control orders, is a red herring. To maintain that it is a "concession" for the Home Secretary to allow judges to issue such orders is to turn our entire legal tradition on its head. It is judges, not politicians, who have the power to imprison people in this country. And in any case, this would still not justify the reversal of the presumption of innocence that this Bill would introduce.

To hear the Prime Minister making the case for this Bill yesterday was to be reminded of the folly of entrusting this particular government with any further powers. Tony Blair took to the airwaves to warn of "several hundred people" in Britain plotting to commit acts of terrorism, citing this as a reason why these restrictions on our liberty are necessary. We have, of course, heard such blood-curdling warnings - supposedly based on infallible secret intelligence - from the Prime Minister before. Did he not shamelessly distort the evidence of Saddam Hussein's weapons of mass destruction to suit his desire to invade Iraq alongside President Bush? It is unsurprising if we are sceptical to hear Mr Blair again citing secret intelligence to support his own suspect political agenda.

The Prime Minister has accused those who are opposed to this legislation of being in a state of denial about the threat posed by terrorists. This is simply untrue. The guilty plea of Saajid Badat at the Old Bailey yesterday for conspiring to cause an explosion on an aircraft is a sobering reminder of the threat we face. But this case actually provides a strong argument for dealing with terrorists through the courts. Consider how Badat, a British citizen, was brought to justice. He was arrested using good intelligence and prosecuted in the usual, traditional manner. This is the way that a democracy should deal with the threat of terrorism.

Mr Blair also accuses his opponents of failing to put forward alternative proposals. Again, this is untrue. We, along with others, have urged the Government to use pre-trial hearings and intercept evidence in court. This should help to gain convictions, while at the same time protecting intelligence sources. His Government has chosen to reject these constructive proposals out of hand.

For almost eight years, Mr Blair's government has steadily eroded civil liberties that have been fought for and protected over the centuries. It has diluted the citizen's right to trial by jury. A person can now, in some instances, be tried twice for the same crime. There are plans afoot to introduce identity cards and laws to restrict our freedom of speech in the shape of a law against incitement to religious hatred. Anti-social behaviour orders have been elevated into this government's primary tool of social policy. It is through similar court orders that the Home Secretary now proposes to undermine the British citizen's freedom from arbitrary detention.

This stealthy erosion of our civil liberties must go no further. We cannot allow any more of our fundamental rights to be discarded by a government that has shown itself to have such scant respect for the conventions that guarantee our freedom. Enough is enough.