The Irish Ambassador to the US has criticised a New York Times columnist for his use of the term "leprechaun" when referring to Ireland.
On 7 June, the paper published a column by Paul Krugman entitled "Yellen's New Alliance Against Leprechauns".
"So let me tell you about Apple and the leprechauns," Mr Krugman wrote in reference to Ireland's corporate tax regime.
It is not the first time the economist has used the term, who previously coined the phrase "leprechaun economics" when describing the impact of multinational companies on Ireland's GDP.
In a letter to the New York Times, Irish Ambassador to the US Daniel Mulhall said he was writing to the paper to express his disappointment.
"This is not the first time your columnist has used the word 'leprechaun' when referring to Ireland, and I see it as my duty to point out that this represents an unacceptable slur," Mr Mulhall wrote.
"I do not go along with Mr Krugman's disingenuous excuse that 'the Irish have a sense of humour' about his attacks on us," the letter read, adding that "derogatory references in a leading newspaper like yours are no laughing matter".
Mr Mulhall said that Ireland has been fully engaged in international discussions on corporate tax reform, and had changed its tax code in line with new international norms agreed to thus far.
"Further agreement in this area cannot be arrived at through name-calling and national stereotyping," he wrote.