Venezuela alleged that Spain's former socialist Prime Minister, Felipe Gonzalez, had joined a plot of ultraconservatives to overthrow President Nicolas Maduro's embattled government.
The Venezuelan President said on Tuesday Madrid's leftist former head of government had signed up with a group of far-right plotters in Spain, Colombia and the United States.
Spain's Gonzalez, who was in power from 1982-1996, rolled out modernisation in the European state, which focused on social welfare and where economic growth was left to markets and EU subsidies.
"Now they've got Felipe Gonzalez, who has just signed on openly – bringing in a great big salary in euros – to the campaign against Venezuela, to support a coup in Venezuela, the coup against me," Maduro alleged in his weekly address on state media.
Just Monday, a source close to Gonzalez told AFP that the former Spanish prime minister, a lawyer by training, would represent jailed members of the Venezuelan opposition, Leopoldo Lopez and Antonio Ledezma, at their families' request.
Causing foreign intervention in Venezuela
Maduro further alleged that the far-right coup plotters "don't know what our constitution says, and they are trying to cause foreign intervention in Venezuela."
Maduro recently accused Washington of backing an opposition plot to overthrow him in a coup that he says would have involved bombing the presidential palace – charges that the US government has dismissed as baseless.
Responding to the allegations, Gonzalez told Spain's Cadena Ser on Tuesday, that Venezuela's government "is failing seriously on two issues that are very basic to a state being able to function," referring to the economy and increasing public insecurity.
The latest accusations from Caracas come as relations between the US and Venezuela hit new lows this month after President Barack Obama slapped new sanctions on the Venezuelan government, calling the country "an extraordinary threat to the national security" of the US.
An angry Caracas responded by recalling its envoy to Washington and ramping up its military status, while Cuba was quick to defend its political and economic ally; Venezuela supplies 60% of its oil.
The Cuban administration called the sanctions "arbitrary and aggressive". Evo Morales, the Bolivian president also demanded Obama "apologise" to Venezuela for its threats or the US would face 'anti-imperialist governments'.