Prisons could run out of space to hold more criminals within the next three years and some higher-risk inmates are already being detained in low-security jails, a new report has warned.

The Commons Public Accounts Committee condemned the Government’s “failure” to improve the estate and said many prisoners are living in unsafe, crowded conditions.

MPs highlighted budget cuts over the past decade and said outsourcing to private firms in a bid to save money echoed the “disastrous” 2014 reforms to the probation service, which was brought back under public control this year.

The report, published on Friday, said only 206 of 10,000 new for old places the Government committed to create in 2016 have been delivered.

“Almost two-thirds of adult prisons in England and Wales are already crowded, with the top 10 most crowded prisons running at 147% or higher than their intended capacity,” it said.

“Demand for prison places could outstrip supply by 2022-23.

“A lack of capacity within some types of prison means that many prisoners already live in unnecessarily stringent security conditions while others live in low-security environments relative to their higher risks.”

The report said the Prison and Probation Service (HMPPS) has a backlog of maintenance work expected to cost more than £900 million, resulting in 500 prison places being taken out of action each year because of their poor condition.

MPs also criticised the Ministry of Justice (MoJ) for an inability to answer “basic questions” about women’s jails, with female inmates accounting for 5% of the prison population.

Labour MP Meg Hillier, chair of the committee, said: “The scale of failure, in our prisons and in the disastrous probation reforms, is really quite staggering.

“The apparent disregard for the position of women in prisons is just another indictment of a clearly broken system.

“The ministry is still reeling from the long-term consequences of its unrealistic 2015 spending review settlement, but our whole society is bearing the financial and human cost of sustained under-investment.

“Even now, we are not convinced MoJ and HMPPS have the ingredients for an effective, sustainable long-term strategy.

“We now expect a set of reports to be made to us over the coming months, assessing the realistic costs of their mistakes to date and how to fix them, and a credible new plan for a working prison estate and system that can reduce re-offending – not just lock people in to this cycle of violence and harm.”

An MoJ spokesman said: “We are investing £2.75 billion to modernise the prison estate and deliver 10,000 new prison places – strengthening security and boosting rehabilitation. Work is already under way on two modern prisons at Glen Parva and Wellingborough which will create 3,360 new places over the next three years.

“We also want to see fewer women go to prison in the first place, which is why we have invested in community services that support vulnerable offenders to turn their lives around and are trialling residential women’s centres as an alternative to custody.”