The Telegraph reports a continental example of the kind of robust European racial humor that would be completely unacceptable in the politically correct United States.

In an episode that could potentially strain relations between Warsaw and Washington, Radek Sikorski, an Oxford-educated politician who has lived in the US, was reported to have made the jibe by an opposition politician, Ryszard Czarnecki.

Writing in his blog, Mr Czarnecki, an MEP, quoted the foreign minister as saying: “Have you heard that Obama may have a Polish connection? His grandfather ate a Polish missionary.”