Considered by the Spanish government to be the political branch of the terrorist organisation ETA, the Batasuna, Unity in the Basque language, party is in the cross-hairs of Spain's justice system and the government of Prime Minister Jose Luis Rodriguez Zapatero's government.
The crackdown against the organisation intensified after June 2006, when the ceasefire agreement between the government and ETA was broken.
After the arrests on Wednesday, September 24, of 11 alleged members of Batasuna in the French Basque Country, Zapatero, said yesterday, while in New York for the UN General assembly, that he does "not exclude the possibility of asking France to ban Batasuna".
In a press release a couple of hours later, Javier Zaragoza, Spain's attorney general, is urging "unconditional collaboration in order to establish a penal process enabling the banning of Batasuna in France".
These statements come in the midst of violent retaliatory actions in Spain's Basque Country, where a police officer was killed in Santona (Cantabria) on September 22 in one of several attacks to take place over recent days.
The French-Spanish collaboration has proved to be the cornerstone in the fight against radical separatism.
"In the 80s, France viewed ETA as a Spanish problem." Antonio Elorza, a political expert at Madrid's Complutense University, told France 24. "In those days, members of ETA travelled to and fro between the two countries completely at their ease. Since his arrival in power, Nicolas Sarkozy has made a huge contribution to Spain's struggle against ETA."
Even if the French branch of Batasuna does play an important role in the organisation, it is less active than its Spanish counterpart.
"There's a big difference between Batasuna in France and in Spain," said Elorza. "Batasuna in Spain is clearly the political arm of ETA, like Sinn Fein and the IRA in Ireland. ETA is active in Spain and until now, 15% of the Basque population has supported the terrorist organisation. That's why ETA has a special rapport with Batasuna, a rapport which couldn't exist in France – popular support there is much more limited. So Batasuna's strategies are different on the two sides of the Pyrennees, but they are complementary."