He told North West Tonight that he believed his party was in the end punished by the electorate for the covid lockdowns of 2020 and 2021.
He said he disagreed with the extent of lockdown restrictions, but acknowledged the pandemic “was a hellishly difficult time to be prime minister”.
As for the reasons for the Tories’ loss in the Labour landslide election in the summer, he said the “the turmoil within the party and the fact that we changed our leader so often” were crucial.
“The brief but damaging period of the Liz Truss premiership with the mini-budget and the consequences from it, obviously caused significant problems.
“But I would say more fundamental than that… is the repeated lockdowns during covid had a series of consequences for the country,” he said.
Sir Graham, who now sits in the House of Lords, said he left politics because he was, at 57, “still young enough to pursue other opportunities”.
Kingmaker: Secrets, Lies, and the Truth about Five Prime Ministers will be published on 26 September.
