THE use of cannabis and hard drugs in Scottish jails will continue to be punished equally despite yesterday's announcement by the Home Office Prisons Minister in England and Wales that inmates caught using cannabis there would be treated more leniently.

The Scottish Prison Service said yesterday it would watch the English policy change closely to see if there were lessons to be learned.

The independent prisons inspector for Scotland, Mr Clive Fairweather, has urged on at least two recent occasions that the SPS should go down the road of differential punishments to reflect what was happening in society and to offer an incentive to prisoners to stay off heroin.

In his annual report, he said the scale of punishments should be reviewed as individual responses varied greatly. In his interim report on Perth Prison in January, he stated it might be necessary to review the punishments for cannabis use ''to increase the incentives for eschewing Class A drugs''.

Mr Fairweather is expected to return to the theme in his annual report this summer. Mr Alan Howarth, the English Prisons Minister, announced yesterday in a new Government policy approach that there would be greater discrimination in punishments, and that drug tests would be more carefully targeted to focus on prisoners with serious drug problems.

The new strategy did not mean the Government condoned the smoking of cannabis in jail, he emphasised.

''The law outside prisons recognises that cannabis is a less serious problem than heroin or cocaine and we are simply reflecting that,'' he said.

He maintained that mandatory drug testing, introduced by the Tories, was working.

The chief inspector of Prisons in England, Sir David Ramsbotham, who recently said the English jails were in the grip of drug barons, welcomed the new strategy for targeting suppliers and dealers and also the renewed focus on hard drugs such as heroin.

''The problem in prisons is not separate from and must not be separated from the problem that is in society as a whole,'' he said.

Mr Paul Cavadino, principal officer of the National Association for the Care and Resettlement of Offenders, said moves to develop more treatment programmes were welcome because the evidence suggested that every #1 spent on drug treatment programmes saved the taxpayer #7, with most of the saving coming from reductions in the cost of drug-related crime.