Gordon Brown has spoken movingly about the moment he realised his first child Jennifer Jane was going to die, days after she was born.
The Prime Minister fought back tears as he told interviewer Piers Morgan how he had turned to a doctor in front of his wife Sarah and asked him whether their daughter would not survive.
"We thought everything was fine. She had... she had been born prematurely but I'd been there at the birth. I'd seen this lovely baby. She was certainly getting special, special care in an incubator. But everybody was very positive and optimistic," he said in the interview to be shown on ITV1 on Sunday.
"It only gradually dawned on us. Nobody actually really told us for a week, it just gradually dawned on us that, that something, something was going wrong and she wasn't getting bigger, she wasn't growing and no matter what treatment that was being given to her she, she wasn't able to respond to it... and then probably after a week Sarah and I... she was in the special care [unit]. I turned to the doctor and I said, 'She's not going to live is she?' And he said, 'No, I don't think so. She's not going to live.'"
Mr Brown went on: "So we had a weekend where we just knew that she was not going to... not going to survive. And she was baptised and we were with her and I held her as she... as she died... this is the happiest time of your life and then suddenly it becomes the most grief-stricken time of your life. It was such a pendulum swing."
Mr Brown suggested his partnership with his wife was so strong because of the tragedy. "My admiration and respect and love for Sarah just grew and grew and grew."
After their second son Fraser was born with cystic fibrosis, Mr Brown admitted: "We sometimes say well, why, why, why, why us? You know, why did this happen to us? But... I feel we've been pretty fortunate in life, because although we've had these tragedies we've been given the privilege of having a son even though we lost a daughter, and then our second son... nobody thought that that would be possible either. So we, we feel pretty fortunate."
The Prime Minister, who has not talked in such detail about his family before, revealed how he proposed to his future wife on a remote beach in Scotland on the night of the new millennium on 1 January 2000. He called the relationship a "modern love story".
Mr Brown admitted he is "determined and strong-willed" but denied he was "grumpy". He acknowledged that he needed to "get better" at presentation, saying: "I'm not very good sometimes at presenting what I do... But deep down I'm actually thinking about how we do things rather than how we say things."
The Prime Minister made his most candid admission of the "tensions" and "fights" between him and Tony Blair since the death of the then Labour leader John Smith in 1994. Admitting that he felt he was the right person to become party leader, he said: "I believed I could do the job, I believed that I'd built up the experience to do it.
"I don't deny there were fights about different issues but it's always the case. In fact it's better to be open and honest and say there were disagreements about certain things but at the same time we managed, I think in the national interest, to get... to get things sorted out."