"I have given this job my all, but you have sent a clear signal that the government of the United Kingdom must change, and yours is the only judgment that matters," Sunak said in a speech to voters outside the prime minister's office in Downing Street.
"I have heard your anger, your disappointment and I take responsibility for this loss. To all the Conservative candidates and campaigners who worked tirelessly, but without success, I'm sorry that we could not deliver what your efforts deserved."