Morocco and Spain traded new accusations on Monday in a diplomatic row triggered by the Western Sahara territorial issue that led this month to a migration crisis in Spain"s enclave in northern Morocco. Spanish Prime Minister Pedro Sanchez described Morocco"s actions in appearing to relax border controls with the enclave of Ceuta as unacceptable and an assault on national borders. Morocco"s Foreign Ministry meanwhile blamed Spain for breaking "mutual trust and respect", drawing parallels between the issues of Western Sahara and Spain"s Catalonia region, where there is an independence movement. The dispute was sparked by Spain admitting Western Sahara independence movement leader Brahim Ghali for medical treatment without informing Rabat. "It is not acceptable for a government to say that we will attack the borders, that we will open up the borders to let in 10,000 migrants in less than 48 hours ... because of foreign policy disagreements," Sanchez said at a news conference. Most migrants who crossed into Ceuta were immediately returned to Morocco, but hundreds of unaccompanied minors, who cannot be deported under Spanish law, remain. The influx was widely seen as retaliation for Spain"s decision to discreetly take in Ghali Morocco regards Western Sahara as part of its own territory. The Algeria-backed Polisario seeks an independent state in the territory, where Spain was colonial ruler until 1975. Describing Spain as Morocco"s best ally in the European Union, Sanchez said he wanted to convey a constructive attitude toward Rabat but insisted that border security was paramount. "Remember that neighbourliness ... must be based on respect and confidence," he said. Morocco"s foreign ministry said in a statement that Spain violated good neighbourliness and mutual trust and that migration was not the problem. Rabat added that it has cooperated with Madrid in curbing migrant flows and in countering terrorism, which it said helped foil 82 militant attacks in Spain. The case of Ghali "revealed the hostile attitudes and harmful strategies of Spain regarding the Moroccan Sahara," the ministry said in a statement. Spain "cannot combat separatism at home and promote it in its neighbour," it said, noting Rabat"s support for Madrid against the Catalan independence movement. Separately Ghali, who has been hospitalised with COVID-19 in Logrono in the Rioja region, will attend a high court hearing remotely on Tuesday from the hospital, his lawyer’s office said. Morocco, which has withdrawn its ambassador to Madrid, has said it may sever ties with Spain if Ghali left the country the same way he entered without a trial.