Venezuelan opposition candidate says letter conceding election was coerced

Maduro aides brought him the letter at the Spanish embassy in Caracas and, he wrote, "I had to either sign it or deal with the consequences."

Gonzalez Urrutia added "There were very tense hours of coercion, blackmail and pressure. At that point, I considered I could be of more use free than if I were imprisoned."

The letter, he said, was worthless as it was tainted by "coercion."

Within hours of polls closing, the CNE declared Maduro the victor with 52 per cent of votes cast.

The opposition immediately cried foul and dozens of countries refused to recognize Maduro's claim to a third six-year term unless the CNE published a detailed vote breakdown, which it has not.

The United States has said there was "overwhelming evidence" that Gonzalez Urrutia had won.

The opposition presented its figures based on polling-station-level counts that it says prove Gonzalez Urrutia won by a landslide.

'Will not be silenced'

Gonzalez Urrutia vowed on Wednesday that "as the president elected by millions and millions of Venezuelans who voted for change, democracy and peace, I will not be silenced."

He left for Spain under the cloud of an arrest warrant -- condemned by the international community -- for "serious crimes" related to his insistence that Maduro had stolen the vote.

Gonzalez Urrutia had ignored three successive summonses to appear before prosecutors investigating him for alleged crimes including "usurpation" of public functions, "forgery" of a public document, incitement to disobedience and sabotage.

The charges stem from the opposition's publication of voting results, which the government says only authorized institutions have the right to do.

The CNE has said it cannot publish the voting records as hackers had corrupted the data, though observers have said there was no evidence of such interference.

Gonzalez Urrutia's lawyer Jose Vicente Haro told AFP on Wednesday his client had been the victim of "blackmail" by the Maduro government.

In the hours leading up to his departure for Spain, Haro said he saw a man "under a lot of pressure, in a situation of coercion, under a situation of urgency, with little chance of speaking" in a video call.

"I saw a person broken psychologically, emotionally," he added.