Steve Richards: Gordon Brown is playing political games with a debate that is both sinister and silly

The Government's approach to terrorism is confused and incoherent. Bravely, and with good cause, the Home Secretary, Jacqui Smith, defends the Metropolitan police chief, Sir Ian Blair, from the media mob that is gunning thoughtlessly for his scalp. She would have secured easy credit if she had been more supine and withdrawn her support. Instead, she and Ken Livingstone chose the thornier path, defying the mighty media and the pathetic Tory and Liberal Democrat members of the Greater London Assembly who dance to the newspapers' tunes.

But while courageously defiant in the face of fashionable cries for a resignation, she and Gordon Brown engage in populist games. By reviving unnecessarily the debate over the need to detain suspects without charge, they play to the same gallery as those calling for Sir Ian Blair's head.

On Tuesday the Labour MP and former deputy leadership candidate, Jon Cruddas, argued on the BBC that while Tony Blair appeared to be acting for crude political reasons in relation to this issue, Gordon Brown has worthier motives. Mr Cruddas is a thoughtful politician, not afraid to speak his mind and to challenge the Government. He is a very useful witness for Mr Brown and one to be taken seriously. But in looking into this again I see no evidence for his optimistic assertion. Like his predecessor, it seems that Mr Brown also calculates that there are advantages for him in this highly-charged debate.

Here is a cause that places Mr Brown effortlessly in alliance with public opinion and right-wing newspapers. It allows him to appear strong and to argue that the Conservatives are weak. He can also exploit the deep divisions on the Conservative benches, where libertarians sit uneasily with social authoritarians. With the wave of a wand the issue enables him apparently to lead a big tent once more.

Once more such political calculations prevail over other considerations. There has not been a single occasion when police have required an extension to the current 28 days. Not once since the issue was last explored only two years ago have the police cried out: "Help, we need more time!" Yesterday, in his dignified responses to the Greater London Assembly, Sir Ian Blair revealed that over the last four years the police have been involved in 12 major counter-terrorism operations relating to London. This is a frighteningly high figure and one that counters definitively the view of some liberals that the threat is exaggerated. Nonetheless, the police have managed to deal with these major threats within the current constraints.

In an outstanding speech in the Commons yesterday, the shadow Home Affairs spokes-man, David Davis, outlined the arguments against an extension with a forensic precision. Mr Davis has been weakly populist in calling for the head of Sir Ian Blair. But in his speech yesterday, he avoided banalities and instead built up a densely compelling argument. In one section he cited in detail a recent police investigation of suspects, showing that officers did not have to work around the clock in a desperate attempt to conclude their work. Comfortably, they managed it within 28 days.

During his speech there was an illuminating and sympathetic intervention from the Labour MP Chris Mullin. The former Home Office minister wondered where Tony Blair's original demand for a 90- day extension had come from. Mr Mullin had been told authoritatively that no such request had originated from the Crown Prosecution Service or the police, a revelation that puts Tony Blair's messianic crusading on this issue in an even worse light. From somewhere a figure of 90 days had been plucked unthinkingly from the air and presented as if it were a life or death matter. As Mr Davis argued, this proposal aims to create " a permanent undeclared state of emergency". It was being rushed through two years ago and is in danger of being rushed through again.

Do not knock Jacqui Smith for declaring yesterday on the BBC's Today programme that she did not know how long the extension should be. Ms Smith should be praised for lapsing into candour, perhaps unintentionally. No one knows what such a limit should be. This is what is so absurd about the meaningless machismo in relation to setting some maximum limit. And yet it appears that Downing Street itself is knocking Ms Smith. Within hours of her interview yesterday, Downing Street made clear that Mr Brown wants a 56-day limit, making Ms Smith's apparent flexibility seem an act of weakness. But why does Downing Street want 56 days? Why is it not 59, or 61, or 78, or 29? This debate manages to be both sinister and silly.

Whenever Mr Brown tries to be too clever by half he gets himself into trouble. The message yesterday was not one of bold resolution, but of muddle. Over this, the Government has a lot to be muddled about.

The independent overseer of security legislation, Lord Carlile, points to a more fruitful way forward. Lord Carlile is a Liberal Democrat and therefore does not make statements on this issue casually. He argues convincingly that there may be occasions when the police need more than 28 days to question a suspect. With no political gain in mind he suggests there could be a judicial procedure in place to enable the police to apply for an extension. This seems to be a relatively uncontroversial method of dealing with a minor aspect of countering terrorism. But such a move does not have the headline grabbing appeal of a formalised extension with a big new figure attached to it.

After being unintentionally candid, Ms Smith expressed more mischievously the hope for consensus over the issue. I wonder whether it suits the Government's purpose to get all-party agreement. Shortly after he became Prime Minister, Mr Brown held a private meeting with David Cameron in which he expressed the same hope for consensus. Mr Cameron has not been invited back for further discussions and yet the latest anti-terrorist proposals are soon to be brought to Parliament for another round of political posturing.

In the Commons yesterday, Ms Smith also argued that the threat was growing. I have no doubt that is the case. There is not a single reason why an alliance of Ken Livingstone, the police and ministers should decide together to exaggerate the threat. But the pivotal question is what should be done to counter the threat. There is not a shred of evidence to suggest that an arbitrary extension will make any difference, and it might serve to intensify the threat.

This is not a debate between libertarians and authoritarians. Such a divide elevates the disagreements far too highly. Instead the arguments are over a whopping great red herring, a relatively minor managerial matter bloated into a colossal issue by an insecure government wanting to seem strong when it is being weak.

s.richards@independent.co.uk