A fresh diplomatic spat arose between Venezuela and Spain this week, culminating in both countries summoning each other's ambassadors. The row, which began over Venezuela’s political prisoners but escalated after Venezuelan President Nicolás Maduro called Spain’s prime minister a “racist,” marks the latest round of tension in a long history of diplomatic scuffles between the two countries.

Members of Spain’s legislature passed a resolution this week calling for the release of Venezuela’s “arbitrarily detained” political prisoners, including protest leader Leopoldo Lopez, who has been in jail for more than a year, and Antonio Ledezma, the Caracas mayor who was arrested earlier this year on charges of being behind a coup attempt. Maduro took to his weekly television program, “In Contact With Maduro,” to rail against the move.

“I am prepared for a battle with Madrid,” he said. “If they look for us, they will find us. They already found us.” He said Spain should focus on its domestic problems rather than focus on Venezuela’s affairs. “Let them opine about their mother, but don’t opine about Venezuela. It stops now,” he said.

He also accused Spanish Prime Minister Mariano Rajoy of having “historical racism,” saying he was “behind all maneuverings against Venezuela,” and called Spanish lawmakers “racists from the corrupt elite.”

Maduro’s declarations irked Spain’s foreign ministry, which called the accusations “intolerable” and summoned Venezuela’s ambassador in Madrid Wednesday. Venezuela’s foreign ministry also said it would conduct an “exhaustive” review of its bilateral ties with Spain, and also summoned Spain’s ambassador in Caracas.

The incident provoked sharp words from both sides, but spats between Venezuela and Spain have arisen several times since former Venezuelan President Hugo Chavez came to power in 1999. The countries had perhaps their most infamous rupture in 2007, when Spain’s King Juan Carlos asked Chavez, “Why won’t you shut up?” as the president was delivering a lengthy speech at a regional summit.

Maduro has lashed out at Spanish officials more regularly over the past year as Venezuela’s political and economic situation grew more fragile. In February he remarked that there was a Miami-Bogotá-Madrid axis of “permanent conspiracy” against Venezuela’s government. In October, Spain’s prime minister met with Lopez’s wife, Lilian Tintori, which further angered Maduro. Earlier this year, former Spanish President Felipe Gonzalez also joined a group of Latin American leaders planning to support the defense of Lopez, whose trial is expected to conclude in May.