Continued severe restrictions in prisons – in effect amounting to solitary confinement – have created “a real risk of psychological decline” among prisoners, the chief inspector has warned.

In a significant intervention, Peter Clarke has warned the Prison Service it should not simply reimpose the extreme limitations placed on prisoners earlier in the pandemic if there were to be a resurgence of the virus.

The containment of the pandemic in prisons was driven by a highly restrictive regime involving increased time in cells, segregation and a ban on all visits – a regime that Public Health England has said will need to remain in place until April next year.

The Prison Service is in the process of implementing its recovery plan for prisons, which involves individual jails applying for permission to move to a new regime stage and then implementing – when authorised to do so – new models.

The official recovery framework states “progress will be slow and incremental, and restrictions may need to be reimposed in the event of local outbreaks”.

Publishing a review on prison visits during the pandemic, Clarke said: “In prisons, there is now a real risk of psychological decline among prisoners, which needs to be addressed urgently, so that prisoners, children and detainees do not suffer long-term damage to their mental health and wellbeing, and prisons can fulfil their rehabilitative goals.”

He added: “In light of the findings in this report, simply reimposing the restrictions that were necessarily applied in the early stages of the outbreak would be too narrow an approach.

“We have seen many prison leaders who are convinced that they could have delivered more purposeful and more humane regimes without compromising safety, and who are frustrated by the restrictive approach they have been forced to take. Every establishment is different. Local initiative, innovation and flexibility which recognises those differences should surely be encouraged, and not stifled.”

Children in public sector custody lost face-to-face education, and for some exceptionally vulnerable individuals in women’s prisons, who usually benefited from a range of specialist support services provided by external providers, the absence of these services was extremely damaging, Clarke said.

Peter Dawson, the director of the Prison Reform Trust, said: “This vital report shows that the measures prisons have taken to contain Covid-19 are not sustainable.”

The Ministry of Justice has been approached for comment.