Susanna Reid says Piers Morgan "goes too far" on "Good Morning Britain" on a daily basis.
The 48-year-old TV presenter is seen by many as being the calm and patient co-host alongside "unbearable" Piers, and she admits working with the journalist can be tough because he breaks the rules on a daily basis.
She told the Series Linked Podcast: "He goes too far every single morning. Absolutely. I always say, "There's a line there, and you are so way beyond it". But that's part of the drama of the program. People say to me, how far can he go before you actually snap? Well, we haven't got there yet. Yet.
"He'd start a fight in an empty room in terms of opinions. He's not backward about coming forward."
Susanna reacted with horror when she heard Piers was joining "GMB" - which celebrates its five-year anniversary this week with record ratings in the last month - but she now sees him as a "dynamic" part of the team.
Explaining how she received the news Piers was joining the line-up in 2015, Susanna said: "The very first time I was told I was going to be working with Piers Morgan, and the editor came into my dressing-room to break the news to me, and I said, "Are our microphones still on?"
"Because I think it would be better if you muted the microphones, so that the gallery and all the crew behind the scenes don't hear my reaction."
"But he is a brilliant, dynamic part of the team and he's somebody who's provocative and opinionated, he can't stand it when anybody, particularly me, sits on the fence.
"He's not neutral about anything, he doesn't care if he offends people, he loves to wind people up. Which is not me at all, but I think that the balance works really well.
"If you had two people like that, I think it would be unbearable. So even though he has a go at me for, "Oh, you're a bit of a snowflake, and you're woke about this, and you're sensitive about that, and you're sitting on the fence", I think actually you need someone just to level out that outrage.
"And so actually I think that professionally and on air the viewers love the partnership, and they clearly do, because as I say, more and more viewers are watching the programme.
"I remember that launch back in 2014, the critics were out to get us. And it just felt like we had to have nerves of steel to make sure that we ploughed on and produced the absolute best show we could. And we proved all the critics wrong, and five years later, happy anniversary to us, which is fantastic."