Tony Blair has shown he is a threat to our constitution

A deceitful PM with a massive majority. That is the danger that became vivid with the terror Bill

What a week! The system just about worked. I never wanted to find out whether there was anything to prevent a government with a large majority in the House of Commons from taking away our freedoms. In the absence of a written constitution, I feared there wasn't.

Admittedly we hadn't reached the nightmare situation described by Philip Roth in his latest novel, The Plot Against America. In it, Mr Roth has Roosevelt losing the 1940 presidential election to the aviation hero and anti-Semite Charles Lindbergh. As President, "Lyndy" stays closely in touch with grass-roots America. He pilots himself in a single-seater plane to great meetings across the country and remains immensely popular even though his government signs a non-aggression pact with Nazi Germany and Congress, now controlled by his supporters, legislates in a manner inspired more by Mussolini than by the Founding Fathers. President Lindbergh is a thinly disguised version of George W Bush, and Mr Roth's message is that when such populists attain power, traditional restraints fail to impede them.

Instead of the fictional President Lindbergh, we have the actual Tony Blair. The reason why Mr Blair is a serious threat to our long-established constitutional arrangements is that he has no discernible interest in civil liberties. The Prime Minister's entire political philosophy is summed up in one of his favourite phrases: what works. Thus, in describing his aims last week, Mr Blair said: "I have simply been trying to do one thing. And that is to give our police and those who look after the safety and security of our country, our citizens, our families, the powers they need to protect us from those who threaten us with terrorism." What works. No mention of the Prime Ministerial duty of balancing the proper concerns of the security services with the freedom of the individual citizen.

In the event, his Prevention of Terror Bill was substantially amended and made subject to early review. Praise be. Characteristically, however, the Prime Minister couldn't prevent himself from misleading MPs. He informed them that to accept the amendment on the so-called sunset clause "would be contrary to the strong advice given to us by our security services and our police". A few hours later, Lord Falconer, the Lord Chancellor, told the House of Lords that MI5 had not told the Government that the country would be at risk if there were a sunset clause.

Nor are constitutional conventions something that interests Mr Blair. He does not allow substantive discussion of policy in Cabinet. Mr Blair only spends time in the House of Commons when it is strictly necessary. When he announced a key concession during the debate on the Prevention of Terrorism Bill on Friday, he did so on television rather than directly to the House of Commons. Menzies Campbell, the senior Liberal Democrat MP, asked how in these circumstances MPs could properly fulfil their responsibilities. This is the point. Mr Blair doesn't want MPs properly to fulfil their responsibilities.

A deceitful Prime Minister with a massive majority whose only interest is in "what works". This is the threat to the British way of behaving constitutionally. This is the danger that became vivid with publication of a Prevention of Terrorism Bill that would have allowed the Home Secretary of the day to subject British citizens to indefinite house arrest without trial or even knowing why their freedom was being removed. However, in the event, the Prime Minister was opposed.

What is the explanation of this miracle? In the first place, a significant if small number of Labour MPs remained unconvinced. Indeed, in one division the Government would have lost had the opposition parties mustered their full strength. Second, Mr Howard's Tories overcame their fears that opposing the Bill would enable Labour to accuse them of being soft on terrorism. This was always implausible. People know that Labour has a large majority and can expect to get its legislation through without too much trouble. When it doesn't, the electorate is likely to conclude that there must be something seriously wrong with what the Government is proposing rather than that the opposition parties are playing "silly games", as Mr Blair would have it. Mr Howard, too, spoke consistently well. His TV soundbites clearly conveyed a simple step argument for opposing the Bill.

Third, the House of Lords, like the Tory Opposition, was unabashed. Essentially what happened last week was that the seriousness of the threat to traditional liberties called forth the full forces of opposition in an unusually coherent way. Newspapers were pretty well united in their opposition to the Bill. Her Majesty's Loyal Opposition awoke from its long slumber. The House of Lords behaved with a vigour unexpected from such an aged membership. Only the streets were quiet. Our unwritten, informal, always-in-flux constitutional arrangements just about held. Thank Goodness.