THE number of young repeat offenders on Britain's streets has increased by 60 per cent in a decade, according to police records.

The figures, obtained by David Ruffley , the Conservative police reform minister, also suggest that the number of crimes committed by persistent young offenders doubled in the 10 years to 2008. A persistent young offender (PYO) is defined as anyone aged 10 to 17 who has been convicted in a British criminal court on at least three occasions and reoffends within three years.

Mr Ruffley said: "These figures show that Labour ministers have presided over a decade of yobbery, fuelled by massive increase in the number of repeat young offenders.

"These figures make a mockery of Labour's promises to tackle youth crime.''

In 2008, there were a total of 15,819 PYOs in England and Wales - 60 per cent more than the 9,868 recorded by police forces in 1997.

The number of offences PYOs were responsible for increased by 80 per cent over the same period from 16,010 in 1997 to 28,834 last year.

On average, PYOs account for about two per cent of all offences brought to justice, but in the Metropolitan Police area in 2006, the most recent figures available, they accounted for 13 per cent of such offences.

In the West Midlands, they accounted for almost eight per cent.

The number of PYOs in Sussex increased more than threefold from 99 in 1997 to 362 last year while Hampshire and Suffolk police forces recorded almost treble the number of PYOs last year, 676 and 208 respectively.

In a written parliamentary answer, David Hanson, the Justice Minister, said the figures were designed to measure the efficiency of the youth justice system.

He said: "They are not designed to measure overall trends in youth crime, and will give a misleading picture of the true trend if used for this purpose.''