In a leaked recording which emerged overnight, the foreign secretary reveals his frustration with the process so far, admitting there will be "bumps in the road", and saying Donald Trump would handle talks better.
Johnson told party activists at a private dinner: "Imagine Trump doing Brexit. Hed go in bloody hard … Thered be all sorts of breakdowns, all sorts of chaos. Everyone would think hed gone mad. But actually you might get somewhere."
But Hammond has countered this suggestion, telling reporters: "In my experience a collaborative approach is more productive than a confrontational approach and my advice to colleagues is to engage with European partners."
Johnson also slammed the Treasury for being "the heart of Remain", rubbishing the department's concerns over a hard Brexit as "nonsense".
A spokesperson for May, who is currently out of the country at the G7 summit in Canada, told reporters the Prime Minister still had confidence in her foreign secretary.