Hundreds of prison officers around the country are to hold a one-hour protest today as part of a row with prison service management over new security measures which staff maintain will lengthen their working day.
All prisons around the country will be affected by the stoppage which will take place between 2.00pm and 3.00pm.
Prisoners who otherwise would have been out of their cells at this time are likely to remain locked up for the duration of the protest.
The dispute revolves around measures announced by the Government earlier this year to have airport-style security screening put in place in prisons. The prison service says the measures are necessary to combat the smuggling of drugs, mobile phones and weapons into jails.
The Prison Officers Association (POA) says it supports the new measures but argues that these security checks should take place as part of the working day. It objects to plans by management to have officers clock in after they undergo the security screening.
The POA has maintained that this could take about two minutes for each person and could lead to officers having to queue to get through the security facilities.
It maintains that this could see officers having to attend for security screening on their own time or be marked late for work, even if they had arrived punctually.
Informed sources said that there had been contacts between the parties over recent days but that there was insufficient progress to have the stoppage called off. The POA plans to hold two further one-hour protests later this month.
Prison service management last week proposed increasing the grace period for staff starting their working day from 10 to 15 minutes, with a further five minutes grace provided after lunch.
The POA rejected the proposals as "derisory".