The BBC series was filmed at HMP New Hall, a prison in Yorkshire which holds 400 women. The director, Chris Terrill (HMS Brilliant, Soho Stories, The Cruise), was given eight months' unprecedented access to this closed world. He admits that initially he shared the public view of prison officers: "I thought they'd be rough, tough and unsympathetic, with no humanity about them. The reality, I found, is very different. The modern prison officer is professional and caring."
Last night's programme, "Through the Gates", began with a group of women being delivered by van to the jail and taken through the reception process by officer Debbie Martin, a 31-year-old who joked her way through the indignities of the mugshot and the strip-search. An older officer spent hours on the phone trying to sort out family problems for newcomer Toni, 28, a heroin addict. A darker side of prison reality began to seep through when Toni attempted suicide and six officers manhandled her along the corridor into a segregation cell. The series explores some challenging issues: in the programme to be screened on Easter Wednesday, the Governor, Mike Goodwin, confronts a self-mutilating prisoner in a manner that viewers may find shocking.
I asked six women ex-prisoners and six prison officers what they thought of last night's programme. All the prisoners strongly disapproved of Governor Goodwin. Kay is in her sixties and has served time in Holloway and HMP Bullwood Hall in Essex. "The male officers resort to sarcasm because most of them are either embarrassed or frightened of women prisoners."
Marie, 42, did seven months in Holloway and Bullwood Hall in Essex for cannabis offences. "The reception officer, Debbie, talked to that new prisoner like a kid even though the woman was older than her," she said. "Comments like that are typical and they're just what you don't need when you get to prison.
"Most of the screws aren't sensitive to your problems because they just don't have the imagination to put themselves in your position and consider what you might be feeling like. They regard you as different, criminal, not proper human beings. They gossip about what you're in for, but they're not interested in the problems that got you into trouble in the first place."
At HMP Cookham Wood in Kent, the Governor, Colette Kershaw, disagrees: "My officers would have no knowledge of a prisoner's offence, unless they'd been assigned to a woman as her personal officer."
Kershaw feels that although Jailbirds gives a fair picture of prison life, viewers may miss the underlying tensions: "Officers find certain parts of their work, like the strip-search, just as distasteful as the prisoners do. You can do it in a cold, clinical, professional way, but a lot of officers feel it helps to make a bit of a joke to avoid embarrassment on both sides and relieve the tension."
"It's all about forming relationships," says a male officer, "but that's done later, not at the reception process when a lot of the women are in too much shock to talk. Once they've settled in, they'll be given a personal officer with whom you hope they will form a trusting relationship. I've been in the Prison Service 23 years and the work now is far more interesting because you get more involved with the prisoners."
Anne, a younger officer, says it's important to define the officer's exact role: "Of course there'll always be a divide, but you can still establish a rapport. I say to the women: `I didn't put you in here. The judge and jury did that. It's my job to look after you in here.'"
So what makes a good prison officer? Governor Kershaw and her staff were unanimous: common sense, a sense of humour and good communications skills. As Officer Anne put it: "You've got to be caring and sensitive to prisoners' needs. But then there's the other side, like locking people up and using restraint techniques to take them to the segregation unit. That side of it has to be done with absolute professionalism following the set rules. But you can still personalise it.
"A third of our prisoners here are foreign nationals and we're encouraged to say good morning to each woman in her own language."
"And we do try to influence policy," adds Governor Kershaw. "For instance, most of us think it's terrible that foreign drugs mules can't be held in open prisons. I've made that view known to the Prison Service."
The prisoners agree that personal relationships are what count: "What you want is someone with a bit of experience of life. You want kind-hearted older men and women who can sympathise with your situation and bend the rules now and then."
The women were acutely aware of officers' language and tone of voice; they resented the way the New Hall staff bawled out women's surnames. Language is a powerful indicator of an establishment's culture: the actors in ITV's Jailbirds were shocked when they were taken to HMP Winchester's women's unit to get a taste of prison life. "We turned up at lunchtime and were told the women were `feeding'!" says Debra Stephenson, who plays a lifer.
Jack Ellis played DI Muddiman in Prime Suspect but he is finding his role as a prison officer much more challenging: "We had a prison officer on set to advise us and I was shocked when she showed me how to jangle my keys in front of prisoners to wind them up. I also had to learn a swaggering walk - because you're authority, you're power. You can feel that power and it's destructive. I shout, `Shut it!' on set and all the noise stops. It feels wonderful."
Chris Tchaikovsky and her staff at Women in Prison have been advising the ITV scriptwriters on language and storylines, and she is delighted that so much TV coverage will bring the issue of women's imprisonment into everyone's living room. "Now viewers will see the reality of prison life," she says. "Five hours of TV could achieve more than all our 15 years of campaigning. The institution of prison is brutalising, but it's easy for us to criticise the staff. Control and care just don't go together very well and any amount of training won't help if an officer has to turn the key on a woman who's just learnt that something awful has happened to her child."
The officers agreed that the prison officer's job has moved a long way from the old turnkey's and is far more demanding. But entry qualifications are still low. A 20-year-old with five GCSE passes can be earning up to pounds 17,000 a year after just 11 weeks of training, while a graduate entrant on the fast-track promotion scheme could be deputy governor of a prison, earning up to pounds 31,000, within five years of leaving university.
At the Prison Service Conference in Harrogate last month, the outgoing director-general, Richard Tilt, launched the new Vision mission statement, setting out guidelines for officers to fulfil the Service's twin aims - to protect the public and to deliver constructive regimes - while dealing fairly, openly and humanely with prisoners. But will these lofty aims prove robust enough to turn the screws and make real changes to prison life? Only 10 days ago 22-year-old Theresa Lohinski was found hanging in her cell at New Hall.
Chris Terrill accepts that it will take time to break down the "nick culture". "I've done a lot of police films and you do find policemen who've joined up because they think they're going to get good fights. Of course you're still going to get those people joining the prison service, but the counter-error is only to look at the thugs. There are plenty of prison officers who are going against the grain to try and change things."
`Invisible Women: What's wrong with Women's Prisons', and `Going Straight: After Crime and Punishment', by Angela Devlin, are published by Waterside Press, Winchester