Venezuela's National Elections Council said that Herrero should be expelled for making "offensive statements" about its decision keep polling stations open two hours longer than normal.

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Gustavo de Aristegui, the foreign affairs spokesman for Herrero's party, told Al Jazeera on Saturday: "We were expecting some kind of reaction of this kind from Mr Chavez [Venezuela's president].

"We have been denouncing Chavez's regime and his potential to become a dictator for 10 years now. He has designed a constitution tailor-made for his political ambition."

Aristegui said he was speaking to another Spanish MP in Venezuela who is part of the delegation monitoring the referendum and the "calls were blocked".

"Three or four times the phone was blocked and he was unable to make calls to Spain for a very long time," he said.

Strained relations

Joseph Daul, president of the European Popular Party, said: "This confirms that Hugo Chavez' regime is moving ever further away from the fundamental liberties which should be respected in every democracy."

Venezuela's National Elections Council said that Herrero should be expelled for making "offensive statements" about its decision keep polling stations open two hours longer than normal.

Chavez told a news conference later on Saturday he has faith "that this lamentable incident, caused in an intentional manner by this disgraceful lawmaker, won't tarnish the excellent relations that we have with the Spanish government."

Venezuela's relations with Spain hit a low point in 2007 when Chavez threatened to review diplomatic and business ties after being told to "shut up" by Spain's King Juan Carlos after he interrupted the Spanish prime minister during a summit.

The rift was officially repaired in 2008 during Chavez's official visit to Spain, where he shook hands with the king and discussed a multi-million dollar oil-for-investment deal with Jose Luis Rodriguez Zapatero, the prime minister.

Spanish businesses, including banks BBVA and Santander and oil company Repsol have an estimated $2.4bn invested in Venezuela.