Stanley Johnson abruptly ended a Newstalk interview about his son, the British Prime Minister Boris Johnson.
A former MEP, Stanley Johnson was asked about his son's moral compass by presenter Jonathan Healy - when he decided he had had enough.
He told The Pat Kenny Show: "I'm going to call it a day: I've very much enjoyed talking to you, you have a wonderful country, you're a wonderful interviewer - but I've said all that I want to say at this point.
It comes after Boris Johnson suffered several high profile resignations from his Cabinet on Tuesday.
While a number of junior ministers also followed on Wednesday morning.
One of them - Will Quince - was sent on Monday to defend Mr Johnson on TV.
But Stanley Johnson says he believes his son should hold out at Downing Street.
"I think he should hold on, we have to focus on the essentials here.
"As far as I can see, the record is very good.
"I wasn't particularly, as you know, a Brexiteer - nonetheless the country was becalmed.
"He did get Brexit done and he is now trying to sort out some of the resulting problems from Brexit.
"As far as COVID is concerned it was a fantastic achievement, we are pretty much back to normal in this country.
"It's a fantastic record, and I do not think that it needs to be - as it were - derailed".
Mr Johnson believes his son simply wants to help people.
"As far as I'm concerned there is an absolute willingness to be good to people.
"Sometimes if there have been mistakes it's because he has erred on the side of really trying to protect people, believe the best about them.
"You go all way back to that Owen Paterson business - what was he trying to do? He was trying to do something for someone he liked".
Asked whether his son has lied to the British public, Mr Johnson says: "I have absolutely no idea whether that is true or not. I don't know how you can possibly speak for the British public.
"I do not think he is".
Mr Johnson says the UK is "mired in a discussion of trivialities".
"I think we should absolutely at this moment concertate on the key things... which by the way now also include trying to deal with inflation and the economy," he adds.
Listen back to the interview here: