Labour’s disastrous decision to move more hardened criminals into open prisons will put the public at greater risk, ministers have been warned.

The Ministry of Justice (MoJ) has dropped a requirement for convicts to be on “enhanced” regimes for good behaviour before they can be moved into more lax surroundings up to a year before they are due to be released.

Former justice secretary Sir Robert Buckland declared the MoJ must introduce “urgent” measures to bolster security, amid warnings that more criminals will vanish from open jails.

And prison officers are warning that organised crime gang members are being moved into the estates with “no security or perimeter”.

Sir Robert told the Daily Express: “Without urgent measures to increase security at these redesignated prisons, then the risk of harm to the public will be increased as a result of this decision by the Government.”

David Spencer, head of crime and justice at Policy Exchange, told the Daily Express: “Moving higher-risk prisoners to open prisons is down to a failure, over many years, to build enough prisons.

“It shows the contempt for law and order held by too many in positions of power and influence.

“Ministers need to recognise that they need to fix this and build many more prisons before the next general election – if they don’t the public will rightly punish them at the ballot box.”

A watchdog has reported that organised criminals are moving into the more relaxed jails under the programme, dubbed TPRS12: Temporary Presumptive Re-categorisation Scheme – 12 Months.

Mark Fairhurst, national chairman of the Prison Officers’ Association, told the i the policy was a “panic measure” to ease overcrowding behind bars.

But it is now creating a “public safety risk”, said Mr Fairhurst.

He said: “The knock-on effect is catastrophic.

“More and more people are being sent back into closed [prisons] because they’re bringing in drugs [into open prisons], they’re bringing in phones, they’re smuggling illicit items. It’s a nightmare.

“They’re getting people you never would have sent there in the past, it’s destabilising the open estate,” he said.

“The number of people absconding will increase because people are just walking out. It’s happened already, there’s loads more than I’ve ever seen, they just don’t return from work or home leave.”

Tom Wheatley, president of the Prison Governors’ Association, said: “Prison governors are concerned because you’ve got people who are less compliant, less engaged, and in many cases have less to lose.

“They’ve got no security, there’s no perimeter, there’s literally no fence. Open prisons are open, you can literally walk out.”

Evidence submitted to Parliament’s Justice Committee by the Independent Monitoring Boards (IMBs) – which inspect prisons – said the scheme was causing an influx of “prisoners who were very different to the usual cohort and were unsuitable for the culture and regime offered in open conditions”.

“Several IMBs noted the rise of violence and drug use and a higher proportion of prisoners associated with organised crime groups in open conditions following TPRS,” said the report.

The shocking admissions come after the National Audit Office (NAO) said current prison expansion plans are “insufficient to meet future demand” amid a projected shortage of 12,400 prison places by the end of 2027, with costs expected to be at least £4billion higher than initially estimated.

The watchdog also said the then government’s 2021 pledge to create an extra 20,000 cells spaces by building more prisons, temporary wings and refurbishing existing cell blocks is now not expected to be met until 2031 – about five years later than promised.

As of September, a third (6,518) of the 20,000 had been made available, according to the NAO.

Reasons behind delays include “unrealistic timelines” and overestimating the ability to get planning permission for three out of the six new prisons due to be built.

The plans are now expected to cost between £9.4billion and £10.1billion – at least £4.2billion more than 2021 estimates amid a rise in construction prices, said the report.

The NAO also warned the Government department “does not have any contingency plans to increase prison capacity as it views it has limited options left to do this”.

Sir Geoffrey Clifton-Brown, chairman of the Committee of Public Accounts said: “Prisons are already at the brink and demand for spaces is set to outstrip capacity.

“HMPPS’s prison expansion plan has been beset with delays and costs are expected to overrun by at least £4billion.

“The report makes clear that the Government’s plans will not meet future demand, which is clearly unacceptable.

“The Ministry of Justice has been in firefighting mode, prioritising short-term solutions to the crisis. These are not only expensive, but also increase risks to prisoner, staff and public safety.

“The Government must pull together a coherent and viable long-term plan for a prison estate that meets demand and delivers value for taxpayers’ money.”