When his government commissioned him to create the installation, several eyebrows were raised, and they were not raised in vain, our correspondent adds.
Czech Deputy Prime Minister Alexandr Vondra said he was only informed on Monday that the installation was not the work of 27 European artists, but David Cerny and two colleagues.
Mr Vondra condemned Mr Cerny and said the Czech EU presidency was considering what steps to take before Thursday's official launch.
"An agreement of the office of the government with the artist clearly stated that this will be a common work of artists from 27 EU states," he said.
"The full responsibility for violating this assignment and this promise lies with David Cerny."
Mr Cerny, who presented Entropa to his government with a brochure describing each of the artwork's 27 supposed contributors from each member state, has apologised for misleading ministers, but not for the installation itself.
"We knew the truth would come out," said Mr Cerny. "But before that we wanted to find out if Europe is able to laugh at itself."
He added that Entropa "lampoons the socially activist art that balances on the verge between would-be controversial attacks on national character and undisturbing decoration of an official space".
Mr Cerny first created a splash in the early 1990s when he painted a Soviet tank, a Second World War memorial in a Prague square, bright pink.
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