FASHION, as glossy magazine writers will inform you, can be a terrible minefield, darling.

A garment feted one moment as the essence of haute couture is, the next, mocked as ill-advised bordering on disastrous.

Crushed velvet flares, for instance. What a dash people in the swinging

early-1970s must have cut, swaggering down Carnaby Street with 28-inch bell-bottoms flapping around their ankles. But within months? About as timeless as a pterodactyl.

Or deeley boppers? You may think you looked groovy, wandering around with two pieces of heart-shaped plastic on springs strapped to your head. Your kids certainly don't.

Now another item of clothing could soon be consigned to the scrap-heap.... and not just because wearing one is likely to earn you hoots of scornful derision from contemptuous passers-by.

For under new legislation, your new cooler-than-thou T-shirt could see you arrested and questioned about terrorism. Because terrorism is now so broadly defined by the Government for the purposes of its controversial Prevention of Terrorism Bill that it encompasses slogans on clothing.

Now, I agree not many people are likely to want to have words, 'My comrade blew up four trains in Madrid and all he got me was this lousy T-shirt' stretched across their chests. But suppose someone who was mightily hacked off with Tony Blair's decision to support the invasion of Iraq decided to protest by wearing a T-shirt suggesting the PM should be tried for war crimes or, even more radically, assassinated.

Under the new Bill that may not be construed as free speech but an

incitement to terrorism. That, obviously, is a far-fetched scenario. But the principle is one which civil liberties campaigners fear may come to pass if the Bill, this morning ping-ponging between the House of Commons and House of Lords, makes it on to the Statute Book.

Ministers were forced to draft new legislation after the Law Lords ruled it illegal to detain 12 foreign terror suspects without trial. Three, held captive at Belmarsh prison, London, for three years, were set free this week.

If it is passed, the foreign suspects will be released under 'control orders' restricting their movements and their use of the telephone and the internet and allowing them to be tagged.

Mr Blair, who has already radically re-drawn the Bill to allow judges, and not ministers, to impose control orders, said in the Commons he was not prepared to offer any further concessions. But the Tories and Lib Dems have threatened to block the proposals in the Lords unless the Government caves in to their demands for a "sunset clause" to review the legislation in November, or to strengthen the burden of proof element of the Bill.

Significantly, as the legislation headed for the Upper Chamber, Home Office minister Hazel Blears repeatedly refused to rule out accepting the sunset clause. If neither side blinks, that remains a possibility. But it would spark a major political row, with the opposing sides accusing each other of provoking the crisis and even allowing suspected terrorists to walk free.

In a stormy Commons showdown on Wednesday, observers were left in no doubt that Mr Blair is intent on portraying the Tories as soft on terrorism for discarding advice from the police and security services.

And Mr Howard pointedly accused the prime minister of playing politics with the issue by attempting to use it to suggest only Labour is tough on terrorists. He sneered: "You want to pretend that you are the only one who is tough on terrorism. Isn't it a dreadful measure from a desperate prime minister and shouldn't you be thoroughly ashamed of yourself?"

Mr Blair hit back: "The shame will lie with the Conservative party - faced with legislation to prevent terrorism, faced with legislation advised on us by our police and security services - that are going to vote against it."

If the Bill does fail - and ministers are forced to extend the present laws - the affair is bound become a central part of the looming election campaign. That would inevitably see bitter allegations over who had been responsible for the crisis and which party can be most trusted with Britain's national security.

The Government believes it has the voters on its side. But the Tories may capitalise on the public's distrust of Blair on security issues. Whatever the outcome, the squabbling is likely to be so rancorous, so dig a pair of long forgotten ear-muffs out of the attic.

Updated: 09:29 Friday, March 11, 2005