David Cameron refused to say if he had offered any advice to Rishi Sunak that he may be making a poor decision by leaving D-Day 80th anniversary commemorations early last week.
The prime minister left Normandy before a major international ceremony marking the anniversary of the Allied landings so he could record a TV interview as part of his push for votes in the general election.
Mr Sunak later apologised, saying on reflection it was a “mistake.”
“I’m not getting into advice that I or my department gave,” Lord Cameron, who attended the commemorations as foreign secretary, said.