The former New Labour chief revealed his political career would have been short-lived if a “highly embarrassing” photo from his youth went viral.
Mr Blair was elected in 1997 and went on to be the Labour party’s longest-serving Prime Minister, the only person to date to lead the party to three consecutive General Election victories.
However, appearing on Dave’s Unspun with Matt Forde, he was shown a picture of him aged about 21 appearing to make a rude gesture.
The 63-year-old admitted the picture was “highly embarrassing” as he spoke about singing and playing guitar in rock group Ugly Rumours while he was studying at Oxford in the 1970s.
Tony Blair admitted old pictures shared on social media would ended his prime minister dreams
I was in the band, if we had, had social media at the time, I would certainly not have been prime minister
Discussing the picture, Mr Blair said: “Let this be a warning to any young person who wants a political career.
“When I was in the band, if we had, had social media at the time, I would certainly not have been Prime Minister.”
He added people would have seen “bad stuff” from his past shared across online platforms.
The photo was from his student days in the 1970s
During the interview he also discussed his views about Britain’s relationship with the United States and controversial president Donald Trump.
He revealed it important to establish a “working relationship” with the billionaire, just like he did with various American leaders during his tenure.
Mr Blair added: “People always want me to criticise Theresa May over this but I think the British prime minister should always get on well with the president of the United States, if it is possible.
“It has got its challenge, obviously, but it is important because in the end there are many, many things we are going to be working on together in different parts of the world.”
Remoaner-in-chief: Blair's Views on Brexit Fri, February 17, 2017
Blair will just not give up.
AFP/Getty Images 1 of 6
'It can be stopped, if the British people decide that having seen what it means, the pain-gain analysis doesn’t stack up'
Social media users were riled up by the former Prime Minister’s presence on the television programme.
One Twitter user wrote: “Two wallets Tony, please don’t think for a minute he represents anyone except himself.”
Another posted: “Sorry Matt, I love your show but I can’t watch Blair, I will switch over during the adverts.”
A third said: “You have to be kidding me! Another appearance by Tony Blair, where we heard that all the good was him and all the bad was someone else.”