What impact can it have on a boy if a repressive state serves a banning order on his parents, which among other things requires them to seek permission even to speak to one another?

In the case of Peter Hain, then living in South Africa, and now Leader of the Commons, it helped turn him into a plucky political activist. If his parents’ experience had not yet instilled in him a thorough fear of injustice, he later faced a 10-day trial in Britain, suspected of robbing a bank. Fortunately suspicion was not enough to deprive him of his liberty. In a court of law he had the opportunity to contest the evidence and prove that he had been falsely accused.

It was indeed ironic that it fell to Hain last week to tell the Commons that legislation to allow Britons to be detained in their homes for an indefinite period and without charge or trial would be rushed through the Commons with only a few hours’ debate.

In an article on Thursday Tony Blair wrote: “It is hard to understand how . . . extra time for Commons debate . . . will make a difference.” While that eloquently expressed his disdain for the parliamentary process, his reason for haste is spurious. True, the government’s present legislative authority runs out next month, and the law has in any case been savaged in a House of Lords judgment as discriminatory and unlawful.

But the government should blame itself for bringing forward changes at the last moment. The opposition would have co-operated to allow the present powers to be extended.

Under pressure the government changes its justifications from one day to the next. With thorough parliamentary scrutiny more of its arguments might crumble. Even without the prospect of more time for parliamentary probing the government is hinting that it will compromise further. Blair’s article suggested that he would consider further the Liberal Democrats’ call for a judge, not the home secretary, to initiate the control order that would restrict a suspect’s freedom of movement and association.

Even without the nuisance of parliamentary discussion the government demolished much of its own case last week. For nearly three years it has contended that the foreign suspects held in prison were too dangerous to be let out. Ministers assured us that the detentions were based on the advice of the security services.

In April 2004 David Blunkett, the then home secretary, described as “bonkers” the decision by judges to release to house arrest one of the detained suspects known as “G”. Recently the press was filled with lurid descriptions, presumably supplied by ministers, of how dangerous the detainees are.

Suddenly the government tells us that, after all, the men can be freed, and need not even be placed under house arrest. Such inconsistency makes it hard to trust the government to decide on a person’s liberty.

Just weeks before the election the government has made this issue party political. The real reason for the rush to legislate is that Blair hopes to wrongfoot Michael Howard, the Conservative leader, and to portray him as soft on terrorism.

Howard has shown strong authoritarian tendencies in the past, and it is much to his credit that he is taking a political risk now by opposing the government’s proposals. He believes that suspects could be tried, especially if telephone tap evidence were made admissible in court.

The Law Society has made a similar case. Blair dismisses it airily, but of course the right to a trial should be the presumption in a society that enjoys the rule of law. If the government is right that it is impractical to present evidence and obtain a conviction, it should allow the point to be explored exhaustively in debate.

Seeing Blair use the legislation as a stick to beat the Tories underlines why ministers should not be allowed to decide whether citizens should be locked up. Politicians have a conflict of interest. The home secretary, in reaching his judgment on a particular case, cannot forget that he is part of a government that strikes a political posture of acting tough. If restricting our liberties is seen as an election winner, justice will be the loser.