My unexpected transfer from the DoE to No. 10 Downing Street was not through open competition. The usual system of applying for a vacancy and being interviewed in competition with others did not apply – in those days, at any rate. At No. 10 a system of who you knew operated, as it does so often elsewhere. In my case, Janet Hewlett-Davies, an excellent press officer who worked at No. 10 with the Prime Minister’s press secretary, Joe Haines, introduced me to him at a party.

Joe Haines knew that I had worked at Transport House. After we had gossiped for a while about Labour people, Joe asked whether I would be interested should there be a vacancy for a senior information officer in the Prime Minister’s press office. Would I?! I would have walked to work barefoot for such a job. It might not happen, Joe warned. It would mean an extra member of staff and he might not be able to make a case for it. I was amazed. Surely if the PM wanted an extra press officer he got one, but it wasn’t as simple as that. There were establishment numbers to be considered. I left Joe Haines in no doubt as to my enthusiasm and commitment, and as I left the party, Janet told me she desperately needed someone to share the load, and hoped to be working with me.

Until that conversation I had looked forward to every day at Environment. I thoroughly enjoyed my work and my colleagues, and in such a big department each day brought something new and different. Now there was the possibility of something infinitely more interesting and I was hugely excited. Days turned into weeks with no word from Joe Haines, and gradually daily problems resumed their urgency.

At last a civil service letter arrived at home asking me to attend an interview in Bloomsbury to check my suitability for No. 10. I dreaded it. Would my boisterous days of clubs and pubs in Chelsea be examined? Were my politics too left-wing? Thankfully, it soon became clear that my past late nights were not considered particularly wild. I had never even smoked marijuana. More interesting was a long discussion about CND, which expanded into talking about the nature of the Labour Party and communist influence. ‘Methodism and Marxism’, as Morgan Phillips memorably put it when he argued that Labour was strongly rooted in Methodism. It was an exhilarating experience.

Not long afterwards, Henry James, the chief information officer at the DoE, summoned me to his office. ‘I’ve had a call from No. 10. For some reason they want you over there.’ I said nothing. ‘I don’t want you to go,’ he went on. ‘You’re doing a good job here, and I must remind you that information staff have no home department. You may not be able to come back to us later on.’

‘But surely it’s a great opportunity to learn?’ I said.

‘Well, Joe Haines is only a temporary civil servant and his ways are not ours…’ He stopped there, obviously realising that I was wild with excitement. ‘Well, good luck,’ he said. ‘You’ll start very soon.’

* * *

It was only a few days after this that I received joining instructions to report at ten o’clock the following Monday morning.

On the day, I walked up Downing Street and coincided with a group of tourists about to photograph the front door and the solitary policeman outside guarding it. I felt embarrassed to push past them, and waited until they had moved off towards Horse Guards Parade. The policeman asked me in a friendly Scottish voice for my name and told me to knock on the august door.

I recognised the entrance hall from a previous visit when the staff of Transport House had been invited to a party to celebrate the general election, and also from television pictures of Prime Ministers shaking hands with their guests in front of a big fireplace. A uniformed member of staff said, ‘I believe you are for the press office. This way.’ How did he know? I followed him along a corridor and into what I recognised with relief as a press office: overflowing piles of papers on chairs and tables; Janet on the phone; Joe with his jacket off, talking to someone at the end of a long table. Janet waved, Joe smiled. ‘Welcome Barbara … can’t stop George, this is Barbara.’ He disappeared into a large room with windows looking on to Downing Street.

I was welcomed by George Holt, the principal information officer. He was a career civil servant nearing retirement, very formal in his speech and writing. He was not happy about the informality with which Janet and I talked to journalists. ‘But we know them, George,’ we’d say, when he suggested we were lowering the tone of the office. He always answered the phone with ‘The Prime Minister’s press office here, Mr George Holt speaking.’ He was immensely hard-working and researched endless facts and dates for Joe’s morning briefings, afterwards following up with more background information on questions which had arisen. Joe, the quick, tough, ex-political editor of the Daily Mirror, treated George with careful politeness, explaining his needs in much more detail than his shouted requests to us.

The press office in those days was a large room dominated by a beautiful old table, its deeply polished surface pitted with the weight of heavy typewriters. George sat at one end and there were piles of newspapers at the other. Janet and I sat opposite one another on either side. There were several telephones, internal and external directories and wire baskets for incoming and outgoing post. For me the beauty of our work was that, generally, it was so immediate. Every call, perhaps with a follow-up call for additional information, was a task completed. Almost all enquiries were from political journalists often requesting only a date or name, but sometimes, a call could turn into a long policy briefing – particularly if the journalist was from a regional paper.

There were no facilities for lunch, and most staff brought sandwiches which they ate at their desks in winter and in the park when the weather grew warmer. George always went out; Joe would lunch in the press gallery at the House of Commons on the rare occasions when he was not the guest of a journalist or editor. When it was very busy, Doris, a permanent member of the No. 10 staff, and responsible for our clerical support, fed us unlimited tea and coffee. She was very down-to-earth. Recruited straight from secretarial school, Doris had seen many great men come and go, and enjoyed telling us stories about Churchill’s deafness and the old deaf butler who looked after him at No. 10 dinners. The butler had painful feet and would cry aloud, ‘Why can’t they all go home?’

In between calls, we read everything we could find. George threw a fat file over to me. ‘This is prepared by the Society of Genealogists,’ he explained. ‘They give us a family tree for all incoming Prime Ministers, and then we add to it.’

I saw what he meant. In addition to the Wilson family marriages and offspring, going back through many generations, there was a ragbag of current information – the PM’s shoe size, for example. It’s very detailed because you never know what might be asked for, especially by foreign journalists. They were looked after by the Foreign Office, but we also received many unusual questions from them.

Gradually I became used to going through the front door, and could confidently find my way around the main offices. I learnt that the Scottish policeman who had first welcomed me was a poet, who wrote in a much-loved Scottish dialect known as Lallans – and that the switchboard were the most dedicated group in No. 10, and gave the very best Christmas party. These ladies, who made and received calls to world leaders everywhere, were hugely intelligent and very responsible, as well as fashionably dressed and made-up despite being hidden from public view. They liked my Cornish accent, which pleased me no end. That was how communications were way back in the ’70s.

One evening when things were quiet, Janet took me to see the Cabinet room and its library. There is a tradition that every Cabinet minister on retirement should give one of his books to No. 10. I looked at some of them, heavy tomes on economic or foreign policy, each signed and dated, but a few books of poetry, too, including one by Enoch Powell.

Every morning there was a meeting in Joe Haines’s beautiful room with the Lobby correspondents. This was the group of political journalists who had special privileges. Everything Joe said was off the record, and this convention was usually honoured. These briefings enabled Joe to announce the PM’s diary and give the background to that day’s political stories. George Holt always accompanied Joe, and Janet and I took turns at sitting in.

Prime Minister’s Questions were twice a week in those days, and afterwards there was a briefing in the House, in the offices reserved for political journalists. The Palace of Westminster turns into a rabbit warren if you climb the stairs away from the wide corridors and grand public rooms. In the early days I often lost my way as I puffed from floor to floor with the latest hot press release. These meetings at the House were conducted by the Lobby chairman and we were there as guests. The basis of our relationship with the press was one of absolute trust. We relied on them never to quote us and they relied on the honesty and accuracy of our information. Similarly, the whole of No. 10 worked on the basis of trust. Once inside that door, you were treated as one of the family. As press officers, Janet and I absorbed as much information as we could on every current topic. Then, during the odd lull in activity, we talked cooking and theatre, exchanged recipes and became lifelong friends.

Occasionally there was an overseas visit. Janet accompanied Harold Wilson to the Far East and came back with two orchids for me. When Mr Wilson became Prime Minister in 1964, his first visit was to Washington for talks with President Lyndon Johnson. He naturally wanted Marcia Williams, his political secretary, to accompany him. The story runs that Marcia went to see the PM’s principal private secretary to discuss the visit. ‘I’m not sure how we’re going to include you,’ she was told. Then, a few days later, ‘Don’t worry, I’ve fixed it. You can go as Mrs Wilson’s maid.’ I was told that the volcanic eruption which followed was the first time the private office had experienced Marcia’s hurt and anger. If the story was true, I felt she had every right to be angry and insulted. She was a well-educated graduate, an acute politician to her polished fingertips and she had every right to her position as the Prime Minister’s political secretary. The civil servants were arrogant. Was it because she was the first woman to hold that position? It should not be forgotten that Marcia Williams was one of those first few women who pushed open the door through which so many other women have followed.

* * *

My friends were impressed with my new position. What was it like? they wondered. Rather odd, I thought, because I had never been in a place where everything was so totally dominated by one man. Although I rarely saw Harold Wilson, I knew, as did every member of the staff, where he was and what he was doing almost all the time. The whole building reacted to him and seemed to relax only when the front door closed on his retreating back.

One Saturday afternoon when I knew the PM was at Chequers and unlikely to appear, I took Robin to look round the famous establishment. She was gratifyingly impressed when the duty policeman greeted me by name and when my knock was answered immediately. I ushered Robin inside, where she lowered her voice as if in church as she looked around the hall, but perked up when she saw the press office. ‘What’s that painting behind your chair?’ ‘That’s an Elisabeth Frink.’ I explained that ministers chose art works for their private offices from the government art collection, and that, at No. 10, every room, even the general press office, was hung with fine British art.

As soon as Joe felt that I could be trusted with evening duty, I was added to the rota. Janet was relieved because she and George had worked every other week; now we each worked one week in three. Being on duty meant staying at home throughout the evening and taking calls put through by the No. 10 switchboard. Usually there weren’t many, other than Lobby journalists fact-checking, but sometimes foreign broadcasters rang in the middle of the night. There was one from Radio Sydney wondering why the British loved Australian comedians like Dame Edna and Basil Brush. I wasn’t too keen on being woken up for that discussion. There was only one occasion when I was deliberately unhelpful. We all felt very strongly about apartheid, so I didn’t welcome being woken by a call from South Africa; and when a very Afrikaner voice said, ‘This is Radio Durban. You’re on the air!’ I replied, ‘Oh, no, I’m not,’ and hung up.

All through the spring, speculation about an election excited all the journalists and staff, except Doris. ‘It will give you lots of free time,’ she said, and I realised that, as a neutral civil servant, particularly at No. 10, I could hardly be politically active. The date of the election was announced for 18 June. I had not previously realised the solemnity and beauty of the proclamation. A copy was fixed to the gates of Horse Guards, and I marvelled at the majestic grammatical progress from ‘Whereas’ through to the end of a long paragraph.

Doris was right. We had weeks of nothing to do while Joe went off with the PM and all the political journalists left Westminster. It was an unreal time of long lunch hours in the park in beautiful weather, then devouring all the newspapers, radio and TV reports. We were sure that Mr Wilson would win, so we didn’t bother with too much research into Edward Heath’s background. I, of course, was sympathetic to his interest in the arts, and was uncomfortably aware that Harold Wilson showed no interest in any of the arts at all as far as I could tell. Transport House, too, had been wholly philistine. I also strongly approved of Heath’s support for closer links with Europe. As polling day drew near, all the commentators and all the polls predicted another Labour victory.

On polling day, I voted very early and then drove through brilliant sunshine to Horse Guards Parade where I parked the car. I went into No. 10 through the Garden Gate. Everyone was there. Excited greetings were exchanged. Already a crowd was collecting in Downing Street. Cheers greeted everyone going in or out. Janet and I bought smoked salmon sandwiches and wine for a celebration lunch. But by the afternoon we knew that our clever, patriotic, kind Prime Minister was out and that Edward Heath was in. While we ate our sandwiches the furniture removal vans arrived.

There was no time to mourn. The phones were ringing – when was the Prime Minister going to the Palace? We already knew the short drive had been delayed because the Queen would not be back from the races at Ascot until late afternoon. It was after six when the staff lined the stairs and corridor to applaud Harold Wilson as he left for the Palace. The front door closed. Outside, a huge crowd cheered, clapped and wept. It was the biggest political upset for many years. From behind the curtains in Joe’s office, we watched in tears.