- 29 - Undoubtedly, the principal obstacle to providing decent conditions of detention to prisoners in Greece continues to be overcrowding. 57. One of the elements of the approach of the Greek authorities in tackling this problem is the above-mentioned programme for the construction of new prisons (and prison service drug treatment centres). It would appear that this programme has recently been revised. The CPT would like to receive detailed information on this subject, including in particular on the timeframe for the implementation of the programme and the entry into service of the establishments involved. However, it is unlikely that creating additional accommodation will, in itself, provide a lasting solution to the problem of overcrowding. Indeed, a number of European states have embarked on extensive programmes of prison building, only to find their prison populations rising in tandem with the increased capacity acquired by their prison estates. By contrast, in those countries which enjoy relatively uncrowded prison systems, the existence of policies to limit and/or modulate the number of persons being sent to prison has tended to be an important element in maintaining the prison population at a manageable level. In this context, the CPT wishes once again to draw the attention of the Greek authorities to Recommendation No. R (99) 22 of the Council of Europe’s Committee of Ministers, which sets out the following basic principles: "1. Deprivation of liberty should be regarded as a sanction or measure of last resort and should therefore be provided for only where the seriousness of the offence would make any other sanction or measure clearly inadequate. 2. The extension of the prison estate should rather be an exceptional measure, as it is generally unlikely to offer a lasting solution to the problem of overcrowding. Countries whose prison capacity may be sufficient in overall terms but poorly adapted to local needs should try to achieve a more rational distribution of prison capacity. 3. Provision should be made for an appropriate array of community sanctions and measures, possibly graded in terms of relative severity; prosecutors and judges should be prompted to use them as widely as possible. 4. Member states should consider the possibility of decriminalising certain types of offence or reclassifying them so that they do not attract penalties entailing the deprivation of liberty. 5. In order to devise a coherent strategy against prison overcrowding and prison population inflation a detailed analysis of the main contributing factors should be carried out, addressing in particular such matters as the types of offence which carry long prison sentences, priorities in crime control, public attitudes and concerns and existing sentencing practices." The recommendation also suggests a number of specific tools which can be used to reduce prison overcrowding or to control prison population inflation. The CPT recommends that the Greek authorities continue to pursue vigorously multifaceted policies designed to put an end to overcrowding in prisons, having regard inter alia to the principles set out in Recommendation No. R (99) 22. The Committee would like to receive detailed information on the measures being adopted by the Greek authorities in this respect.