The number of escapes and positive drug tests have been reduced despite a large increase in the number of inmates, according to the latest prison service figures.

BBC Home Affairs reporter Danny Shaw explains the figures (32")

The director general of the service says it has performed exceptionally well, but the Prison Officers' Association (POA) maintains that the performance targets were set so low, it was inevitable that they would be achieved.

Just one of the 11 targets was not met - that of the number of assaults on staff which remains slightly above 9%.

The figures show that there were 105 escapes in 1997/8 compared with 347 five years ago, and none of the most dangerous, category A inmates broke out of jail.

The service says that is because private security firms are getting better at transporting prisoners and improved procedures since breakouts at Whitemoor and Parkhurst.

The number of positive drug tests is also down from 24.4 to 20%, although this figure means that one in five inmates tested have taken drugs.

Mark Healey of the POA believes the figures should not be taken at face value (2'25")

The target of 22.5 hours to be spent on what is described as "purposeful activity", rehabilitation and offender treatment programmes, is also being met, although the POA says this is an example of how the standards set at the start of the year are not stringent enough.

Its Chairman, Mark Healey, said 29 hours a week had been achieved in recent years and this could hardly be trumpeted as a great success.

"Over the last twelve months there have been many, many additional hours worked. Some of our members have been paid for that overtime, some of our members haven't. We don't seem to have stemmed the rise in the prison population," he said.

Richard Tilt paid tribute to staff

The Prison Service's Director-General Richard Tilt said the targets were set by ministers and that the performance, particularly in the areas of security and offending behaviour programmes, had been very encouraging.

He said: "The service has performed exceptionally well this year, and I want to pay tribute to all the staff who have so worked hard to help us meet nearly all our targets.

Prison Service Director General Richard Tilt says the targets are a valid indicator (2'33")

"Standards haven't been reduced over the last few years", he said, and this was despite the increase in the number of inmates - 6,000 in the past year.

The Prisons Minister Joyce Quin said the service had produced an outstanding performance in "what has been a challenging year".

She said: "The way staff have met the increased demands made of them has been magnificent. The reduction in the number of escapes from prisons over the last five years has been remarkable."

But Dr David Wilson, a former prison service manager who is now a criminologist, disputed the relevance of the figures.