How could Liz Truss be forced to quit?

Revealed: four ways that the prime minister might be shown the door

Under Tory party rules, a new leader cannot be challenged through official procedures for at least a year after entering office. But there are other routes. MPs say that if at least half the parliamentary party wanted Truss gone (that is the case already) and they all write to 1922 committee chair Graham Brady to say so, he would then feel obliged to visit the PM and tell her the game was up. If messages were also conveyed from the chief whip, Wendy Morton, and other grandees that she had lost her party in parliament, it would be difficult to fight on.