Amazon “pays little or no taxes to state and local governments, use our postal system as their delivery boy and are putting many thousands of retails out of business,” Trump trumpeted.

But the White House insists that Trump has no grudge about the fact that Jeff Bezos, the founder of Amazon, also owns the Washington Post.

The Post isn't Trump's favourite media outlet after it investigated his donations to charities.

Wall Street appeared to shrug its shoulders after Trump's outburst – Amazon's share price remained more or less stable.

[Photograph courtesy of Chensiyuan, Wikipedia Common. Pictured is Oxford's "Bridge of Sighs"]