In the eleven years I’ve been an MP many people have told me they want CCTV cameras in their neighbourhood. I don’t remember anyone ever asking for them to be removed.

David Davis, the Tory MP fighting a by-election, now thinks CCTV cameras erode our civil liberties and Mr Cameron is backing his re-election. You and I might think being the victim of a mugger or a vandal is a greater loss of liberty – but not it appears Mr Cameron’s Conservative Party.

They also say we should ignore the advice of the police over investigating terrorism.

In our legal system, once charged, you cannot be questioned about the offence you are charged with. So the police investigating a terror plot either have to release their suspects after 96 hours or charge them and stop asking for the information needed to prevent an attack.

That was why the law was changed a few years ago to allow the police, in terror cases only, to apply to a judge for permission to hold someone for 28 days without charge.

But now the police say that the plots they are investigating are becoming more complicated and they say that in the future 28days won’t be long enough to investigate them. They say they will need 42days. The Government is backing the police, the Tories are not.

I could understand the Tory position if the police were being allowed to hold people on a whim but they are not. Under the Government’s proposals, to hold someone for 42days the police will need to be investigating a serious terrorist threat and within 48 hours of arresting someone they must get a judges permission to detain him, the judge must be convinced the threat is serious and the police are doing their best and must renew that permission every 7 days.

If they can’t do the work they need inside 28 days the police will then need to ask the Home Secretary to enact the power that would allow 42 day detention and the Director of Public Prosecutions must support their request. The Home Secretary has to make their request public and put it to Parliament within 8 days. The judge can then allow the suspect to be held – and thus questioned – for up to 42days before being charged but only if he is convinced it’s necessary.

Lives depend on the police succeeding in catching terrorists. Each plot can require hundreds of computers to be searched, evidence collected in several countries and thousands of leads followed up and if a suspect needs to be detained while this goes on a judge will be protecting his rights every step of the way.

But if the Tories are ever in charge, and won’t back the police, who will be protecting the rights of law abiding citizens by standing up to terrorists?