The Number of children and teenagers regularly committing crimes has soared since Labour came to power.

Rural areas have been worst hit with counties such as Sussex, Gloucestershire, Dorset and Suffolk showing the biggest increases in youth offending.

The Conservatives said the figures showed that Government plans to try to cut youth crime were not working.

The figures show that over the past decade the number of persistent young offenders (PYOs) in England and Wales has jumped by two-thirds from 9,868 in 1997 to 16,512 in 2007.

A persistent young offender is defined as "a young person aged

10 to 17 years old who has been sentenced by any criminal court in the UK on three or more occasions''.

The offences must be "notifiable'', ranging from murder to grievous bodily harm, assault, sex offences, robbery, burglary, car theft and drugs offences.

Only six out of 63 regions in England and Wales saw falls in such crimes committed by persistent young offenders.

Rural counties were hit hardest. Sussex, Gloucestershire and Dorset saw increases of 242 per cent, 111 per cent and 151 per cent respectively.

Separate figures, released in a Parliamentary answer, also showed that the number of convictions for persistent young offenders shot up by 92 per cent, from 16,010 in 1997 to 30,683 in 2007.

Last night, David Ruffley MP, the shadow police reform minister who obtained the statistics, said: "These figures make a mockery of the Government's strategy to tackle youth crime. There have been 46 strategies since 1997 with provisions to try to tackle youth crime. These figures clearly show that they have failed.''

Justice minister David Hanson said the large increase in offenders could be explained by an improvement in courts' convictions.

It now took just 65 days - not 141 days - from arrest to sentence for an offender.

This boosted the figure, he said, because "the definition of a persistent young offender relies on counting successive sentencing occasions for a single offender during a limited time period.

"Speedier operation of the youth justice system has markedly reduced the average time taken from arrest to sentence. As a result the number of young offenders who fall within the scope of this definition has increased.''

However Mr Ruffley dismissed Mr Hanson's explanation as a "risible excuse''. He said matters were made worse because each offence meant that police had to fill out forms and hand them to the Crown Prosecution Service.

He said: "Under Labour's bureaucratic statutory charging scheme, the police cannot charge PYOs.

"They have to prepare a case file and wait to receive the decision from the Crown Prosecution Service. This wastes police time.''

Last month The Daily Telegraph revealed that rural areas have suffered higher increases in violent crime than the rest of Britain since Labour came to power.

Offences of "violence against the person'' for the 13 counties in England and Wales which are officially defined as rural jumped by more than 83,000 a year, a 119 per cent rise, compared with a 108 per cent increase nationally.

A spokesman for the Home Office said a youth crime action plan which would improve public confidence in the justice system would be published this summer.