Belgium has apologised to the Dutch prime minister after the Belgian foreign minister likened him to the fictional boy wizard Harry Potter.
Belgium's Karel de Gucht is no stranger to controversy
Karel de Gucht said he meant no offence when he said Jan Peter Balkenende was "a mix between Harry Potter and a brave rigid bourgeois" with no charisma.
Mr de Gucht also called Dutch voters "superficial and unreliable" for rejecting the EU constitution.
The Dutch have summoned the acting Belgian ambassador for an explanation.
Dutch Foreign Minister Bernard Bot will "make clear that such remarks directed at the prime minister and the Dutch people are inappropriate", the Dutch daily Volkskrant cited a ministry spokesman as saying on Monday.
Mr de Gucht said he had sent Mr Balkenende a letter of apology on Saturday.
"If Mr Balkenende has a problem with my statement, then I have no problem in apologising," Mr de Gucht was quoted as saying by Belgian media at the weekend.
Mr Balkenende has been likened to Harry Potter before
Mr de Gucht said he was trying to highlight the volatility of the Dutch electorate by comparing popular support for the Dutch prime minister with that for the late Dutch politician Pim Fortuyn.
"All of a sudden masses of people supported an extravagant, militant homosexual with a deviating opinion and chauffeur-driven Bentley," he was quoted as saying of Mr Fortuyn, in an interview at the weekend with Het Laatse Nieuws newspaper.
"Then, those same masses elect Jan Peter Balkenende, a mixture of Harry Potter and inoffensive small-mindedness, a man in whom I detect no trace of charisma.
"And then there was the Van Gogh murder," he added, referring to the killing of Dutch filmmaker Theo van Gogh, allegedly by radical Islamists.
The Belgian foreign minister has got into hot water over undiplomatic remarks before.
Earlier this year, the Democratic Republic of Congo recalled its ambassador to Belgium after Mr de Gucht made critical remarks about Congolese politicians while on a visit there in October.
The Congolese government accused him of behaving like Tintin, the colonial-era cartoon adventurer.