It feels nerve-wracking to be interrogating such a practised interviewer as Sue MacGregor, but it’s a testament to much how she puts people at ease that it’s an enjoyable experience.

MacGregor and fellow broadcaster Joan Bakewell will use their well honed interview skills on each other for an event in aid of Primrose Hill Community Library.

“She’s far more experienced at being interviewed than I am. I don’t do that many but when I did I rather enjoyed it, unless I suspected they were going to turn it into a harangue against the BBC,” says the Primrose Hill resident.

Recently interviewed on Dermot O’Leary’s Radio 2 show, she found it a “delightful experience”.

“He’s my kind of interviewer, genuinely interested in the person he was talking to which is not always a given these days when so many shows are built around the personality of the interviewer.

“I was brought up hundreds of years ago to listen to the person that you are talking to. The hardest thing during interviews on radio is listening to the answers instead of thinking ‘what’s my next question, how many minutes have I got left?’ often with the producer saying something in your ear. You have to grasp that the other person is the one the audience wish to hear.”

It’s strange to think that the woman who co-helmed Radio 4’s flagship Today programme with John Humphrys and Brian Redhead started her BBC career in 1961 as a lowly secretary.

“I didn’t go to university I’m an auto didact and at 19, I was the secretary to the secretary of a programme called In Town Today. I never thought I would be in front of a mic. I thought I would be a PA to someone or at best a producer.”

MacGregor frequently calls herself “lucky” but intelligence and tenacity must have also played a part in her triumphing in a male dominated environment.

“In those days the only women in the newsroom were sitting at typewriters taking dictation from male correspondents. There were no women reading the news, no foreign correspondents until Kate Adie. If you got married you had to give up your job and reapply for it.

“It’s changed out of all recognition. No news programme worth its salt would have only male presenters.”

It took travelling back to Cape Town where she grew up and where an “enlightened male boss” gave her a shot as a reporter to kickstart her broadcast career. Returning to London in 1967 she landed a job as a reporter on the World At One.

“One of the main reasons I have been lucky enough to have a big career is I never had children. (Today hosts) Mishal Husain and Sarah Montague both have three. I so admire women who have the responsibility of running a family and do live broadcasting on a programme as huge and demanding as Today.”

She adds: “To sustain a long career you need an element of luck and tenacity. Turn up on time and deliver the goods. Everything’s down to that.”

MacGregor’s honest about encountering sexism in her career, and getting fewer big political interviews than male colleagues Humphrys and Jim Naughtie.

“I did around 30 percent. I didn’t get them as often as I would wish but I could see the producers had a dilemma because the chaps kicked up sometimes if they didn’t get the top interview and I thought they were more experienced than I was.”

Some men openly disliked being interviewed by a woman – including cricketer Geoffrey Boycott. Just before she was scheduled to interview him MacGregor got a message in her ear “this one’s going to John Humphrys. Afterwards I asked what had gone wrong and was told Boycott had said ‘I am not going to speak to a f***ing woman.’”

But female interviewers could be just as difficult. When Spartacus and Guys and Dolls star Jean Simmons arrived at the studio wearing dark glasses and a huge floppy hat it didn’t bode well.

“I’d grown up watching her movies with Stewart Granger and was longing to meet her, but it was clear she didn’t want to do this interview. For a long 12 minutes she barely said anything at all.”

The scientist Miriam Rothschild was also “difficult but entertaining”.

“She asked in advance what my questions would be. When I told her she said “I’ve never heard such stupid questions!’ at which the green light went on, we were on air and I had to ask them anyway.”

But during the ‘80s and ‘90s she did land the tough interviews on South Africa and is proud that through her contacts her current Radio 4 show The Reunion managed to seat ANC, white nationalists and security police around a table to discuss the release of Mandela

“It was quite a gripping programme. When there’s tension it makes good radio.”

With forthcoming programmes reassembling key players in the Maastricht Treaty and the arrest of Pinochet, it’s clear the versatile and unflappable MacGregor is still in the thick of it. She says: “The Today programme played an extraordinary part of my life. 17 years of getting up at 3am and finished by 9.30am.

“I always went for a swim afterwards to clear my head and always wore make-up because by the time you left the building, people were coming to work and you couldn’t look like an unmade bed.”

Joan Bakewell and Sue MacGregor are at Cecil Sharp House in Regent’s Park Road on May 5 at 7.30pm. Tickets £15 only from Primrose Hill Books 134 Regent’s Park Road. primrosehillbooks.com