Walk down any high street in Britain today and you will instantly be under surveillance. All around you, lampposts and shopfronts bristle with CCTV cameras, many of them privately operated and unregulated. They are watching you in case you are bent on shoplifting or engaging in violent disorder.

As you pass the Post Office, it is unlikely to occur to you that the Royal Mail’s investigators have the power to mount surveillance or intercept operations if they suspect you of mail theft.

The man on his knees rifling through the pile of rubbish by the kerb is not, as you might have thought, a tramp but a fly-tipping investigator from the town hall. He and the officials in the council offices down the road have the power, should they chose to use it, to recruit informants to spy on fly-tippers, dodgy stallholders and housing benefit cheats.

And the young girl rattling the collection tin on the opposite pavement might well be under surveillance by the Charity Commission’s investigation branch, which doubts the validity of her fundraising activities.

Covert surveillance, once the stuff of John le Carré novels and the business of the Stasi in East Germany, is a constant reality in 21st century Britain. The power to spy on the average Briton is widely held, extensively used and, as the revelations of the past week have confirmed, sometimes misused.

Whether you are an MP, a lawyer or an ordinary citizen you can be followed, bugged and watched while your telephone calls and e-mails are intercepted by an ever-increasing range of public bodies.

Organisations such as MI5 and MI6, GCHQ and the Serious Organised Crime Agency use bugging and tapping as everyday tools of their trade. But surveillance and interception are also increasingly used by police forces across the country. The rural West Mercia Constabulary, for example, recently advertised for “substantive constables” to fill posts in its Covert Authorities Bureau.

In prisons, Category A prisoners routinely have their phone calls taped and a police intelligence unit is based at Prison Service headquarters.

As you go about your daily activities, you can be followed by men or women from the Office of Fair Trading, the Health & Safety Executive and the Rural Payments Agency. The Charity Commission, the Food Standards Agency and the Royal Pharmaceutical Society of Great Britain can seek authorisation to conduct surveillance operations against those they suspect of wrongdoing.

Every one of the 474 local authorities in the country has the same right and can seek permission to examine your phone records, text messages and e-mail history.

Sir Christopher Rose, the Surveillance Commissioner, reported a rise in the number of local authorities using their powers of surveillance. “Covert activity is still most often used by departments that deal with trading standards and with antisocial behaviour and by those that administer benefits,” he said in his annual report.

Sir Christopher, who is conducting the inquiry into the bugging of the MP Sadiq Khan’s conversations with a terrorist suspect, said there were 40,000 surveillance operations mounted during 2006-07. Only 67 of these were unauthorised.

Another regulator, Sir Paul Kennedy, the Interception of Communications Commissioner, reported this month that 122 local authorities had sought communications records to identify offenders such as “rogue traders, fly tippers and fraudsters”. Six fire authorities had obtained communications records.

The human rights group Liberty reported last year that Britain led the world in the proliferation of CCTV cameras with an estimated 4.2 million across the country. Bar possible planning issues, there is no law to prevent an individual installing a camera at his home. London’s Congestion Charge camera network is also available to Scotland Yard’s Counter-Terrorism Command, which can watch watch live footage of suspect vehicles crossing the capital.

The National DNA database holds the genetic profiles of 3.9 million people in Britain, many of whom have never been convicted of an offence.

By 2010, the Government plans also to establish the compulsory National Identity Register holding a wide range of personal information as part of a national identity cards scheme.

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