The UK's ambassador to Tehran has responded angrily after a senior Iranian minister claimed the British were inhuman idiots led by a stupid Prime Minister.
Iran's first vice president, Mohammad Reza Rahimi, was quoted as saying that the UK's inhabitants were "not human" and "a bunch of idiots run by a mafia".
In a reference to Prime Minister David Cameron he reportedly added: "The young lad in charge now is even more stupid than his predecessor."
UK ambassador Simon Gass wrote a strongly-worded reply on the British embassy's website on Tuesday, which he linked to his Twitter page.
He said in a statement in the Farsi language, which was translated by The Times: "To discuss the political differences between countries is natural.
"But when a high-ranking official who represents the Islamic Republic of Iran makes such insulting remarks about the people of another country, it reflects badly only on the person who made such remarks.
"To state that the British are not human and to call them thick shows a lack of respect for human dignity, and is an illogical and worthless remark."
Mr Rahimi did not restrict his ire to the UK when he spoke at an education conference on Monday.
He condemned the countries that have supported the latest United Nations sanctions over Iran's nuclear programme, saying the Koreans "need to be slapped" and denouncing Australians as "a bunch of cattlemen".
The Foreign and Commonwealth Office said Mr Gass's decision to reply to Mr Rahimi's comments did not mark a change in policy, adding: "In this instance we felt the remarks given at an education conference were inaccurate and offensive, and that they merited a response."