The veteran broadcaster was interviewed following the Tory party’s annual conference, held in Birmingham earlier this week.
Truss came to the conference amid widespread divisions within the party, exacerbated by the publication of a “mini-budget” last month that left the economy in crisis.
Speaking to GMB hosts Ben Shephard and Kate Garraway, Dimbleby said: “It’s chaotic isn’t it. I’ve never seen quite such chaos.
“It’s not just the chaos of a party that’s clearly disintegrating before our eyes in the Conservative Party. It’s riven with disagreement. What was going on in Birmingham... unbelievable.”
However, the former Question Time presenter added: “It seems to me in politics these things, they do kind of come and go. I think our politics will settle at some point. We’ve got problems that all parties acknowledge.”
While Dimbleby never interviewed Truss, he did once host her on Question Time years ago. Shephard asked whether she struck him as a future leader of the party.
“No, not… to be truthful. No, we didn’t think of her.
“She was a bit all over the place, we thought, politically and I wasn’t quite sure what she stood for,” he said.
Good Morning Britain airs weekdays at 6am on ITV.
Dimbleby’s interview came as writer and director Russell T Davies responded to the “weird’ similarities between Truss’s conference outfit and the dress worn by Emma Thompson’s fascist prime minister in Years and Years.
Years and Years creator Davies was among those to spot the similarities, sharing a picture of the two outfits on Instagram and writing: “This is getting weird.”
“No f***ing WAY,” commented It’s A Sin star Callum Scott Howells, while Russell Tovey, who appeared in Years and Years, commented with crazy-faced emojis.