By Simon Walters, Mail on Sunday Political Editor
Last updated at 1:23 AM on 07th February 2010
Gordon Brown wept in public this weekend when he talked of the death of his daughter Jennifer and spoke of facing up to the possible premature death of his son Fraser, who has cystic fibrosis - and his hope a cure will be found.
Mr Brown's wife Sarah, who was present, also sobbed in an extraordinary display of emotion when the Prime Minister was interviewed by Piers Morgan for a TV programme.
The candid exchanges, which took place over two-and-a-half hours in front of a live studio audience, are to be broadcast on Piers Morgan's Life Stories on ITV next Sunday.
Gordon and Sarah Brown leave church in Kirkcaldy after daughter Jennifer's funeral service in 2002
Mr Brown told how it was he, and not his wife, who was first to realise that Jennifer was not going to survive. She died in 2002, at just ten days old, after suffering a brain haemorrhage.
'It was so moving, some of the audience were close to tears as well'
He also spoke of his agony at the knowledge that his three-year-old son Fraser may have a 'poor life expectancy'.
A member of the audience said: 'It was remarkable to hear Mr Brown talk like that.
'He said he was the one who could tell Jennifer wasn't going to make it and he described how he held her tiny little hand until the very end.
'He was asked if he was angry about his son's illness and said, "We sometimes ask, why us? But we try not to be bitter."'
During the interview, the famously reserved Mr Brown also talked more openly than ever before about himself and his battles with Tony Blair.
In the frank discussion, Mr Brown:
* Admitted he lost his temper sometimes, but denied he had ever hit any of his aides.
* Confirmed he had 'explosive' rows with Mr Blair.
* Said Mr Blair had secretly promised to hand over power to him - but that the timing lay with Mr Blair.
* Revealed how he proposed to Sarah on a beach and said she was the only woman he had ever loved.
The Browns' first child Jennifer was born prematurely and weighed just 2lb 4oz. She died in the arms of her parents at Edinburgh's Royal Infirmary.
How the Daily Mail reported the tragic death of Jennifer Brown
Fraser, the couple's second son, was diagnosed with cystic fibrosis five months after his birth in July 2006. In the past Mr Brown has raised hopes that despite the condition, Fraser could be 'a rugby player or a football player'.
Another member of the audience said: 'It was so moving, some us were close to tears as well. It was hard not to be.'
The interview followed intense discussions between Mr Brown and his aides over how to overcome the widespread perception that he is dour and remote.
The Prime Minister has refused to follow the lead of Mr Blair, who targeted women's magazines and talked about himself and family matters in order to appeal to ordinary voters, especially women.
And unlike David Cameron, Mr Brown has refused point-blank to allow himself and his wife to be photographed with their two sons.
His decision to open his heart to Piers Morgan is bound to be seen as part of new drive to reduce Mr Cameron's lead in the opinion polls ahead of a General Election - widely expected in May.
Piers Morgan with Gordon Brown
Candid interview: Piers Morgan with Gordon Brown
Mr Cameron is regarded as a much better performer on television than the Prime Minister. But with three televised debates between the three party leaders certain to play a vital role in the outcome, Mr Brown is keen to hone his TV skills.
He told Mr Morgan he was confident he would succeed John Smith as Labour leader when Mr Smith died in 1994, and was devastated when Mr Blair beat him to the job.
Mr Brown confirmed reports dating back more than 15 years that Mr Blair promised to hand over power to him later if he stood aside for him in that initial contest. But he said the secret pact was not reached at the Granita restaurant in Islington, North London, as has been stated, but was agreed before then.
'He was frank about the rows with Tony Blair'
A member of the audience said: 'He was pretty frank about him and Blair. He said they had explosive rows and that he wished he had got the leadership earlier.
'But he said he had had to accept it was up to Blair when he gave way to him. He did not dispute he had a temper, but said suggestions he had hit his staff were nonsense.'
The programme includes filmed interviews with Mrs Brown, the Prime Minister's two brothers John and Andrew, as well as Tony Blair and Peter Mandelson.
It is not the first time guests on Mr Morgan's show have cried.
Model Katie Price - aka Jordan - was reduced to tears as she revealed how she had been sexually assaulted as a child, while Welsh classical singer Katherine Jenkins cried when she recalled how she was nearly raped as student.
And Sixties pop star and TV host Cilla Black sobbed when describing the death of Ellen, her premature baby.