The commission that oversees US presidential debates says it will change the format to ensure the remaining two encounters between Donald Trump and Joe Biden are more orderly. US media report that one new measure could be to cut the microphones if the candidates try to interrupt each other. The announcement follows Tuesday’s ill-tempered debate that descended into squabbling, bickering, and insults. The tone and tactics of the first presidential debate were criticised across the US and around the world.