Thousands of prisoners will be able to make phone calls from their cells under a Government drive to improve rehabilitation and stem the flow of illegal mobiles.
Justice Secretary David Gauke will announce plans to invest £7million on introducing in-cell telephones for more jails in England and Wales.
The technology is already in place at 20 establishments, and plans are under way to extend the scheme to another 20 over the next two years.
Currently, most prisoners queue for public phones on the landings, which can be a trigger for violence or fuel demand for illicit mobile phones, the Ministry of Justice said.
Officials emphasised that in-cell phones are subject to strict security measures.
All calls are recorded, users can only call a small number of pre-approved numbers, and active monitoring can be introduced if there is any suspicion the service is being abused for crime.
Prisoners will continue to pay to make calls, the MoJ added.
The move forms part of efforts to improve inmates' ability to maintain ties with relatives after they are jailed, which is seen as a key factor in reducing the chances of returning to crime.
Last year, a report by Lord Farmer found that good family relationships are "indispensable" to the Government's prison reform plans.
In a speech, Mr Gauke will say: "Decency also extends to how we treat prisoners - fairly and consistently, with time out of their cells, activities, and the opportunity to maintain family relationships.
"As Lord Farmer made clear in his ground-breaking review last year, supportive relationships are critical to achieving rehabilitation."
The announcement on in-cell phones forms part of a £30million package to improve safety, security and decency across the prison estate following several years of surging levels of violence, self-harm and drug use.
In another step, every prisoner will be given a "risk rating" under plans to choke off the influence of criminal kingpins behind bars.
Inmates will be assessed according to their chances of taking part in violence, escapes, disturbances and gang activity.
The new digital tool - which is being rolled out across the estate following a pilot in 16 jails - compiles data from law enforcement databases and prison incident reports.
The MoJ said the intelligence will allow police and prison staff to better target their activity to prevent, disrupt and disable criminal networks, including moving prisoners when necessary.
As a result of the new approach, nine prisoners have already been moved and another three are awaiting transfer.
Authorities estimate there are around 6,500 prisoners with links to organised crime in England and Wales.