Sir Kim Darroch resigned last week after extracts emerged from memos he'd apparently written, in which he described Donald Trump’s administration as “clumsy and inept”.
The former UK ambassador to the US made his decision to step down after Boris Johnson, the current frontrunner to replace Theresa May as British Prime Minister, had refused to support him during a leadership debate.
Foreign Office minister Alan Duncan told the BBC that the leadership favourite had thrown Mr Darroch "under the bus" by refusing to give him his backing.
But who stands to profit from the demise of the ambassador?
Tim Marshall examines the ins and outs of a political power game that has parallels throughout recorded human history.
Watch the latest edition of Sightline above.
