The last bastion of free smoking in the UK is set to be shut down, after the Prison Service confirmed it was considering plans to ban smoking in prisons.
Prisons in south-west England are set to be part of a pilot ban, with the entirety of the prison system expected to follow suit by 2015.
About 80% of prisoners smoke and tobacco often functions as a form of currency on prison wings, leading many prison experts to warn that the move could trigger disorder.
"Prisons are going through unprecedented budget cuts, prison resources, staff resources have been cut," Andrew Neilson of the Howard League for Penal Reform said.
"There may well be good intentions behind this policy proposal, but it will undoubtedly put a lot of pressure on jails which are already pretty stretched."
Sadiq Khan, Labour's shadow justice secretary, said: "Recent prison inspection reports show they are increasingly stretched on a daily basis battling simply to stop disturbances.
"A smoking ban in prisons without planning and resources seems an odd priority at a time when David Cameron's out of touch government has failed to deliver a so called 'rehabilitation revolution'."
Under existing arrangements prisoners cannot smoke in indoor public areas but they are allowed to smoke in their cell as they are defined as "domestic premises".
Non-smoking prisoners are never forced to share a cell with a smoker.
The new plans would ban smoking in cells and even outdoor public areas like exercise yards.
"We are considering banning smoking across the prison estate and as part of this are looking at possible sites as early adopters," a Prison Service spokesperson confirmed.
In a letter to senior staff and seen by the Times, the service said: "You will no doubt be aware that the decision has been made that the time is right for the prison estate to adopt a tobacco and smoke-free policy to provide a smoke-free workplace/environment for our staff and prisoners."
The ban is a key demand of the Prison Officers' Association since the ban on smoking in public places in 2007, with the union saying its members could otherwise be at risk of second hand smoke.