cannabis let-off for 1,000

Government figures reveal 1,027 formal warnings - which let users off without a criminal record - were doled out for possession of pot in 2006 to 2007.

This was up by 83 per cent on the number dished out in 2004 to 2005 - when police were first told not to prosecute most minor first-time offenders. There were 560 formal warnings handed out for cannabis possession in 2004/05 and 1,023 in 2005/06.

Cannabis was downgraded from Class B to Class C in January 2004, and officers were given the power to issue an official reprimand instead of having to pursue criminal charges against anyone found in possession of the drug.

Cannabis is still illegal, but police will now usually only prosecute if there are aggravating factors, such as smoking in a public place or repeat offending.

Further action is also taken if someone has already received two warnings.

Prime Minister Gordon Brown launched a consultation in July on reclassifying cannabis, following growing concerns that stronger varieties of the drug - such as skunk - can cause mental health problems.

It is likely it will upgraded back to a Class B drug.

The figures were published by Justice Minister Maria Eagle in a Parliamentary written answer.

Other large urban forces have also seen increases in the number of formal warnings dished out for cannabis possession, but the number of warnings in Derbyshire fell by 25 per cent from 665 in 2004/05 to 497 last year. South Yorkshire Police Detective Superintendent Adrian Teague said: "South Yorkshire's figures are in line with a national trend. South Yorkshire Police continue to take seriously the misuse of all controlled drugs, including cannabis.

"The use of formal warnings, which go on a person's record, is just one means of dealing with such offending, together with diversion and rehabilitation initiatives in the county, which are equally important."