When education minister Esperanza Aguirre announced her project for a common, national syllabus in the humanities she must have been aware of the hornet's nest she was about to stir up.
She was antagonising her party's parliamentary allies, the Basque and Catalan nationalis ts whose support keeps the Spanish government in power.
It is Ms Aguirre's wish to change the history syllabus which has caused the trouble. At present, Spain's education authorities set 65 per cent of the syllabus with each of the country's 17 regional authorities adding the rest according to their own criteria. In the case of Catalonia, the Basque Country and Galicia, regions with their own language, the figure is 55 per cent.
Ms Aguirre wants to replace this system with the introduction of 174 common topics, which would remove the regional differences and place a much greater emphasis on Spain as a national entity.
The Catalan nationalist party, Convergencia I Unio said the proposed changes fly in the face of the strongly decentralist Spanish constitution, which recognises the separate rights of Spain's regions. Catalonia's education secretary has said that the government would have to pay "a very high price" - essentially a threat of withdrawal of parliamentary support.
However, a recent report has shown that regional variations in history teaching are much more than merely differing interpretations of facts. Instead, accounts vary widely, usually in favour of the region concerned.
The effect of this, said Joaquin Prat, a history professor at Barcelona University, is to encourage antagonism, division and even xenophobia. So varied are the versions taught that Spanish publishers have to produce seven versions of textbooks to concur with regional demands.
One example is the account of Ferdinand of Aragon and Isabella of Castille, the Catholic monarchs of the 15th century. Textbooks in the Castille region identify Queen Isabella's crucial role in Columbus's voyage and the reconquest of Spain but make no mention of her husband, King Ferdinand. In Catalan history books, however, the latter receives the praise and Isabella is hardly mentioned.
In the Basque Country which considers itself to comprise parts of southern France as well as northern Spain, history books treat both France and Spain as neighbours.
In a recent interview with the magazine Marie Claire, ex-prime minister Felipe Gonzalez expressed his dissatisfaction with the way regional considerations are promoted at the expense of national history. It was during Mr Gonzalez's period of office that the law reorganising Spanish education, LOGSE, was passed with the backing of the nationalists who insisted on the right to make regional modifications to the history syllabus.
Ms Aguirre's decision to address the situation is the latest episode in a stormy 18 months at the ministry of education. Teachers bemoaned her lack of knowledge of educational affairs, though many agree that regional bias in history teaching needs to be tackled.
Carolina Torres, 39, history teacher at Silverio Lanza secondary school in Madrid, said: "History teaching is manipulated by regional authorities and this should be corrected. But Aguirre's approach is impractical as she wants to bring in a much bigger syllabus, yet with no increase in the number of hours. The new syllabus is impossible because there's no time."