Who could it be?

There is a new parlour game in Washington: Name the White House Mole. These are the odds from Bovada, the betting website.

Jeff Sessions, attorney general: 5/2

A frequent target of the president’s wrath – and his demands for the Justice Department to act as his personal defence team.

Mike Pence, vice-president: 3/1

Became an early favourite when online sleuths noticed author’s use of the word ‘‘lodestar’’ – a favourite of his. But Pence’s office has issued a strong denial.

John Kelly, chief of staff: 4/1

The former Marine general has struggled to bring order to a chaotic White House, and leaks suggest impatience with the president.

Nikki Haley, US Ambassador to the UN: 10/1

A favourite of Trump’s, but seen as ambitious.

Ivanka Trump and Jared Kushner, senior counsellors: 15/1

Often seen as liberal voices of reason. But would Ivanka really do this to her own father?

Don McGahn, White House counsel: 15/1

He’s leaving soon so has little to lose, and has clashed with Trump over Russia.

Donald Trump, president: 25/1

OK, a joke, but he did like to pose as his own spokesman back in New York. Could he be trying to stir up his base?