I'm naturally inclined to support the police when they ask for a change in the law to enable them to do their job, but I have to admit to some pretty serious doubts about the proposal to increase the period in which a terrorist suspect can be held without charge from 28 days to 42.

The counter-terrorism argument is fairly straightforward. The incredible complexity of modern investigations can require the translation and de-encryption of thousands of data sources - as after the July 7 bombings - or involve enquiries on three continents - as in the case of the atrocity that was prevented in London by the car being towed away before its contents could be detonated.

The counter argument is that habeas corpus is a fundamental principle in British law and that by giving away some liberties to protect freedom you end up without a freedom worth fighting for.

The UK has current legislation that enables suspects to be held without charge for longer than virtually any other country, although I accept that many other European nations use the technique of charging the suspect with a minor offence and holding them for years - as is the case currently with the suspects in the horrific Perugia murder of Meredith Kercher.

I don't buy the argument that 42 days will alienate sections of our community. There was plenty of alienation long before the Iraq invasion and September 11 is stark proof of that, but it does seem to me that such a long period of pre-charge detention does immense damage to fundamental aspects of the British way of life.

Of course I respect the police and believe that they should be given the tools they need to keep us safe but sometimes even supporters have to say "no" and I deeply regret that this is one of those occasions.