Prisons minister Rory Stewart is ''disappointed'' that prison staff have chosen to protest over violence, pay and retirement age increase. He says that he is regularly in touch with the Prison Officers' Association and understands the issues raised, but insists that staging a walkout ''isn't the way to go about it.'' Report by Lynaghf. Like us on Facebook at http://www.facebook.com/itn and follow us on Twitter at http://twitter.com/itn