He said he wanted to give Mr Trump the chance to pursue his agenda "without somebody popping off" at every turn. But he suggested there may be limits to his silence.

He has also said he wants to help nurture the next generation of Democrat leaders.

“I think now I have some responsibility to at least offer my counsel to those who will continue to be elected officials about how the DNC can help rebuild, how state parties and progressive organisations can work together,” he said.

At 55, Mr Obama is one of the younger former presidents in US history – only Theodore Roosevelt, Ulysses S. Grant and Bill Clinton were his junior.

He is also one of the more popular.

So the Hawaii-born president has always intended to be active in his retirement – despite revenue from his book sales, plus his $203,700 (£162,798) annual pension, meaning that he can well afford not to work.