David Usborne's report of the spartan wooden bunks and "tiny" exercise area on the prison ship Resolution ("Return of the incredible hulks", 19 January) makes depressing reading. The Resolution cannot possibly meet the standards that the Prison Service applies to new prisons.

Additionally, it can be psychologically damaging for prisoners to feel that they are physically exiled from the mainland. The proposal to hold immigration detainees on the Resolution makes this a particularly acute concern.

The Prison Service should never have been placed in this desperate position by the abandonment of the more enlightened penal policy of the early 1990s in favour of a punitive "prison works" approach.

Paul Cavadino

Penal Affairs Consortium

London SW9