Britain on Saturday said the “barbaric” hanging in Iran of former top defence official and dual British national Alireza Akbari, who was accused of spying for UK intelligence, would not go unchallenged. “This barbaric act deserves condemnation in the strongest possible terms. This will not stand unchallenged,” Foreign Secretary James Cleverly said. Prime Minister Rishi Sunak said he was “appalled”, adding: “This was a callous and cowardly act, carried out by a barbaric regime with no respect for the human rights of their own people.” Cleverly confirmed that Iran’s most senior British-based dip…