Andy Burnham became emotional as he spoke of his late father during his Labour Party conference speech.
The Prime Minister appeared to hold back tears, before taking a pause, which promoted a member of the audience to shout “go on Andy”.
His father Roy, who was in his mid-80s, died earlier this month after suffering from Alzheimer’s.
Mr Burnham has previously spoken about his father’s illness, which meant he did not know his son had become Prime Minister.
This experience is one of Mr Burnham’s driving factors to reform the social care system.
He told the conference in Liverpool he would change the system “in memory of my dad and out of respect for everyone who cared for him”.
Foreign Secretary Ed Miliband, whose mother died in June this year, also appeared teary-eyed as the Prime Minister spoke of the loss of his father.
In his speech, Mr Burnham said he was determined to prove wrong the claim that he would be the UK’s last prime minister, made by Scotland’s First Minister on the day his father died.
He said he was not looking to “seek sympathy” or criticise John Swinney, before adding: “Anyway, my dad Roy would have been the first to defend his right to say it.
“I relay it because I want you to know how it made me feel. Utterly determined to prove him wrong.”
Mr Burnham had also paid tribute to his parents who gave him “a care for people”.
His father was a former telephone engineer, first with the Post Office and then with BT.
He and the Prime Minister’s mother Eileen brought him up in Culcheth, Cheshire, alongside his two brothers.
Speaking on Tuesday, Mr Burnham said his family home was filled “with life, love, and laughter”.
He added: “Eileen and Roy gave me a care for people, forged by her faith, his politics, and the values of this great city we are in again for our conference.
“They guided me to the point where I stand before you today.
“Ours is the same story of so many families, British families of my generation, a story of working-class aspiration, a desire to get on and give back, never pulling up the ladder, and a post-war Britain that backed them to do it.”
After returning to work a few days after his father’s death, Mr Burnham said he would have wanted him to be “back out there” to bring forward “the changes that he always pushed me to make”.
