While Barack Obama and John McCain have been trading blows over who would be the best commander-in-chief, the White House has been working to ensure that the winner of Tuesday’s election will be prepared for the first change in presidential power since the 2001 terror attacks on the US.

Michael Chertoff, homeland security secretary, says the US has no information about possible terrorist attacks during the transition. But the Bush administration – which witnessed the 9/11 attacks just eight months into office – wants to make sure that the next president can respond swiftly to any unexpected national security event.