Spain's new socialist government has challenged the traditional influence of the Vatican by unveiling plans to release the Catholic Church's grip on religious studies in state schools.
The ruling party has also withdrawn state funding from private Roman Catholic schools in one region.
Jose Luis Zapatero's Socialist Workers Party of Spain (PSOE) has lost none of its reforming zeal since it came to power in the spring and it now plans to tackle the ecclesiastic hierarchy's autocratic involvement in state education.
Under the present system, state schools teach Roman Catholicism as an option among others in a curriculum chosen by the Church, which also provides religious studies teachers.
In future, pupils will be able to opt out of religious studies lessons which could cover any faith. The plans mark a dramatic u-turn from that of the previous conservative government, which was set to make Rome's teachings compulsory in all state schools.
The opposition has accused the new government of betraying the country's cultural values.
Popular Party leader Mariano Rajoy said: "Public money should not be spent on teaching faiths that are not part of our culture."
The use of public money to subsidise private schools, many of them run by the Catholic Church, is also at the core of a row between the Vatican and Barcelona.
With its semi-autonomous status, the Catalan city's new socialist government has cut funding for many of the concertadas (subsidised private schools).
Historically, some of Spain's private schools became part of the state system after Franco's death, when the then socialist government was keen to build free public schools quickly.
The answer was to educate up to 30 per cent of pupils at privately-run schools, which were compensated.
Madrid has not said if it will follow Barcelona's example, but has revealed more details of its education reform. More major changes are planned, including new courses on gender equality, environment, sex education and civil rights.
Outlines of the new courses, to be taught under a banner of "democratic and civil values", have been sent to Spain's various regional administrations to test reaction.
"The future law is being discussed right now, with the government looking for a consensus to write the law more precisely," said Daniel Albarrac!n, a researcher at the education and social policy think-tank CIREM, in Madrid.
"It will provide for a more flexible and open model of education."
The course would be compulsory for pupils in the later primary years and the first four years of secondary school, said Mar!a JesNos San Segundo, Spain's new education minister.