Spanish Prime Minister Pedro Sánchez has lamented what he describes as a lack of European solidarity over the Ceuta crisis in a letter to European Commission President Ursula von der Leyen, in which he points to misinformation, prejudice and petty politics.

The letter, sent on Saturday and seen by Euronews, comes after Sánchez described the arrival of 50,000 migrants from Morocco in Ceuta in a single day, after the double-fenced border was breached, as an "attack" and a "violation of Spain's territorial integrity".

In the strongly worded letter, Sánchez describes the response from some EU partners as "rather asymmetric".

While breaches of national borders are often swiftly condemned by member states and often portrayed as hybrid attacks, several EU countries instead called for tighter controls on Spain, urging Madrid to restore order rather than expressing solidarity.

"Most have shown us their support and solidarity, and have offered their assistance," the Spanish premier writes in the letter.