Rishi Sunak
"I think his instinct is almost certainly to go. I hope that he won't," Andrew Mitchell said.
The former prime minister stoked the Tory civil war by launching a fresh attack on her successor.
The deeply-divided party faces a lengthy spell in opposition following its humiliation at the ballot box.
New poll confirms Rishi Sunak's "catastrophic misjudgment".
The former prime minister had to get used to sitting on the opposition benches for the first time.
David Cameron has also resigned from Rishi Sunak's frontbench.
Keir Starmer and his family are taking over.
The ex-home secretary slammed her colleagues, saying she had once been told to "STFU".
Kemi Badenoch, Suella Braverman and Robert Jenrick could all be planning to throw their hats into the leadership ring.
Why Keir Starmer's victory was actually not a straightforward slam dunk.