"While the committee acknowledged progress since previous visits, Scotland’s prison estate continues to face significant population pressures. "We are taking action through investment in community justice, prison infrastructure and measures to safely reduce the prison population. Gray said: "The prison population in Scotland, like many comparable countries, has increased and has reached unsustainable levels which must be addressed. A spokeswoman for the SPS said: "As we have made clear, the size and complexity of the prison population is unsustainable. "We welcome the Scottish Government’s consultation and the wider discussion it has prompted about what is needed to create a safe and sustainable prison population.