Sir Robert Mark, former Chief Commissioner of Police, London, said in a speech :
" In the legal and constitutional framework in which society requires us to enforce the laws enacted by its elected representatives, the most essential weapons in our armour are not firearms, water cannon, tear gas or rubber bullets, but the confidence and support of the people. That confidence and support depends on our personal and collective integrity, and in particular on our long tradition of constitutional freedom from political interference in our operational role.
It is important for you to understand that the police are not the servants of the government at any level. We do not act at the behest of any Minister or any political party, not even the party in government. We act on behalf of the people as a whole, and the powers we excercise cannot be restricted or widened by anyone, save Parliament alone. "
In Regina vs. Metropolitan Commissioner of Police Exparte Blackburn, Lord Denning stated the powers of the police in words which have become locus classicus. That case related to a confidential instruction of the Commissioner of Police that prosecutions under the law against pornography would require his prior approval, although there was no such requirement mentioned in the statute. Striking down the confidential instruction, he observed :
" I hold it the duty of the Commissioner of Police to enforce the law of the land. He must take steps so as to post his men that crimes may be detected, and that honest citizens may go about their affairs in peace. He must decide whether suspected persons are to be prosecuted. But in all these things he is not the servant of anyone save the law. No Minister can tell him that he must, or must not, keep observation on this place or that, or that he must. or must not, prosecute this man or that. Nor can any police authority tell him so. The responsibility for law enforcement lies on him. He is answerable to the law, and to the law alone. "