Charities have warned against new powers that would allow ministers to block the automatic release of dangerous prisoners and potentially make them serve their full sentence.

The rule change is part of measures introduced to protect the public and would allow ministers to override judges’ fixed-term sentences that set automatic release dates at halfway or two-thirds through offenders’ jail terms.

Instead, ministers will be able to refer offenders to the Parole Board so they can serve out their full prison sentences if they are deemed to have become a “significant public protection concern” and pose “a very high risk of serious harm”, according to the Telegraph.

It had been thought that the new power would only apply to criminals who were radicalised in jail and who had posed a threat if freed.

However, the Ministry of Justice guidance seen by the newspaper “lists more than 180 types of crime that can justify extended detention if the prisoner is thought to pose a risk of committing them after release”.

These include robbery, burglary, assault with intent to cause grievous or actual bodily harm, affray, criminal damage, brothel-keeping, carrying a firearm with criminal intent, possessing indecent images, making threats to kill, domestic violence and a number of sexual offences.

The MoJ guidance states the new power will cover all forms of risks posed by the offender upon release, whether terrorist, violent or sexual. It says the power will not allow for the prisoner to be detained beyond the end of the sentence as handed down by the court and that offenders must be released at the end of their sentence in line with the judge’s decision.

According to the new “policy framework”: “The use of this power is reserved for Standard Determinate Sentence [fixed term] prisoners who were not judged to be dangerous at the point of sentence but who are subsequently assessed to pose a significant risk of serious harm to members of the public.”

This power, the MoJ added, will be “rarely used”.

However, Peter Dawson, director of the Prison Reform Trust, who is a former prison governor, cited the Imprisonment for Public Protection sentences, which led to offenders, some of whom had committed lower-order crimes, remaining in jail for years without a release date.

Dawson told the publication: “When a Labour home secretary introduced the now discredited IPP sentence we were all told it would be used rarely.

“More than 8,000 cases later, that sounds as hollow as the assurances being made for this unprincipled transfer of sentencing powers from the judiciary to the executive.”

A government spokesperson said: “Our number one priority is protecting the public. That’s why it is vital we have the power to keep the most dangerous criminals – including terrorist, violent or sexual offenders – behind bars for longer when their release would be a risk to public safety.”