I didn’t think I’d last long with Mrs Thatcher but I ended up protecting her for 20 years

Smart, sexy and with nail-biting tension, it is little surprise Bodyguard is already this year’s most successful drama. The first episode introduced almost seven million viewers to Home Secretary Julia Montague, played by Keeley Hawes, and her guardian David Budd, played by Game of Thrones’ Richard Madden.

The BBC series shows Helmand war veteran Budd torn between being true to his beliefs and his duty to protect a politician who backs military intervention in the Middle East.

Add to that suicide bombers and a simmering sexual tension between the pair, which boiled over last night, and you could feel the script by Line of Duty’s Jed Mercurio is far-fetched.

Until, that is, you meet people who have done the job for real.

Former Special Branch detective Barry Strevens knows how to defend someone you fundamentally disagree with. In 1978, when he found out his next job was safeguarding then-Leader of the Opposition Margaret Thatcher, his heart sank.

The former teacher had always been left-wing and was wary of her divisive politics – and personality.

“When I was first told about the posting, I thought, ‘Crikey, I’m not sure I am going to last long with her,’” says Barry, 74.

But he would serve as the Iron Lady’s bodyguard for 20 years, his loyalty never wavering throughout her successes and eventual downfall.

Barry learned the importance of impartiality, which is crucial when guarding powerful, ambitious figures. He says: “From what I had read about her, I wasn’t sure I was going to make the grade, and she wouldn’t want me. But actually I grew to like her.”

The ruthlessness Thatcher became notorious for in public also carried into her private life.

“I’ve seen grown men cry because of her,” he adds. “I’ve been handbagged twice. I had to tell her something about her son Mark she didn’t like. But she would say to me, ‘Barry, what can I do? He is my son’.”

Barry insists that the level of public hostility Thatcher

I’ve seen grown men cry because of her. I’ve been handbagged twice. But I grew to like her BARRY STREVENS ON THE EXPERIENCE OF WORKING WITH MARGARET THATCHER

experienced throughout her 11-year run as Prime Minister – ranging from assassination attempts to egg peltings – never bothered her. “Whenever I asked her about it, she would say, ‘You can worry about that, Barry,’” he laughs. “I started wearing a raincoat a lot of the time because of the amount of eggs thrown at us.” And he was willing to take more than just eggs for her. Barry, who worked with Thatcher until he retired in 1998, is still “tainted by guilt” that he was not there on the night the IRA bombed Brighton’s Grand Hotel in 1984. He was recovering from an emergency appendectomy when the terrorists struck. “I wasn’t there when she was in the greatest danger of her life,” he says.

And while her tough image was the real deal, Barry insists the Iron Lady, who died in 2013, had a softer side.

“She was good with kids,” he says. “There are two sides to everyone. She showed that motherly side to us.

“On Christmas Eve one year, I got back to a room where there had been a meeting, with a big mess left behind.

“She had cleaned the room top to bottom. There were Christmas decorations, a fire in the hearth, a flask of coffee, a tin of biscuits and a miniature whisky. I told the story at a senior officers’ luncheon and when she found out she said, ‘Barry, if I knew you were going to tell that story, I would have made it a large whisky’.”

The grandad-of-two, who lives in Shrewsbury, says he remembers her irreverent sense of humour well. “She caught some of the guards eyeing up her legs – I think she was quite chuffed actually,” he says.

He then gives a non-committal laugh when asked what Thatcher would have thought of the #MeToo movement.

In Bodyguard, an initially spiky Montague becomes irritated by Budd requesting a diversion for safety reasons, quipping that he is making her job harder.

And Barry admits that in the early days, he annoyed Thatcher too.

“They don’t want someone around them all the time and when they’re on holiday – they’re not used to it,” he says. “But politicians are grateful because they know you put your life on their line for them.

“They try to make life easy for you if they can and you want to make their life as easy as possible. And there is a respect that grows.”

Bodyguard continues on BBC1 on Sunday at 9pm with the first two episodes available now on the iPlayer.