Every January 5th, children around Spain take part in the country's traditional Three Kings parades, an event which sees the Magi distributing sweets by the truckload.
The parade is a highlight of Spain's Christmas calendar and comes the evening before Epiphany, the day on which Spanish children traditionally receive their presents.
But around 800 students at a school in Madrid's southern Carabanchel district have been shut out of a local parade by city authorities because of their ‘Catholic belief system', parents have said in a statement.
In the statement, the mothers and fathers expressed their “disappointment” at the decision, saying they felt “discriminated” against.
But Madrid councillor for Health, Security and Emergencies, Javier Barbero, denies the claims.
He says the city's new left-wing Ahora Madrid council has barred the school from taking part in the parade because of its policy of segregating boys and girls. That is against the rules in the district, he argues.
School district head Gustavo García, meanwhile, points out that the parade organizing committee excludes any organizations which promote discrimination on the grounds of sex, age or any other criteria.
But the school says just two classes are segregated along sex lines, in a policy that only affects ten percent of students, and only some of the time.
And council opponents with Spain's conservative Popular Party have now called for an extraordinary council meeting to discuss the ban.
“This is not just an attack on liberty but also shows a lack of humanity and sensitivity,” said PP councillor for Carabanchel Álvaro González, in calling for a meeting.
The war of words over the Three Kings parade is the latest salvo in an battle between the political left and right in Madrid which has been raging since Ahora Madrid, backed by anti-austerity party Podemos, ended 24 rules of conservative party rule in the capital in June.
Recently, the two sides clashed over the decision of two districts in Madrid to swap a king for a queen in this year's Three Kings parades.
Popular Party councillor Isabel Rosell slammed that move as being nothing more than gender politics in disguise and "lacking in common sense".