'Most difficult hours' for Chavez

Speaking in a national meeting with senior military and civilian officials on Tuesday, Vice President Nicolas Maduro said President Hugo Chavez's breathing had worsened and that he was in the worst state of health since he underwent an operation to remove cancerous tissue in mid-December.

He described an infection that was first announced by Information Minister Ernesto Villegas late on Monday as "very severe" and spoke of "complications in his respiratory situation."

"These are the most difficult hours since his operation... but our supreme responsibility is to keep telling our people the truth," Maduro said.

He also repeated a charge that Chavez has previously made himself, accusing enemies of Venezuela's government of causing the president's cancer.

"Chavez was attacked with this disease... The historic enemies of this nation looked for how to harm the health of our commander," Maduro said, adding that a team of scientists would be given the task of uncovering evidence of this.

The vice president also announced that a military attache who had been posted to the US embassy in Caracas had been ordered to leave the country within 24 hours for allegedly plotting against the Venezuelan government.

As Maduro spoke, dozens of supporters of the leftist leader gathered in prayer outside of the military hospital in Caracas where the 58-year-old president is being treated.

The government has revealed little in the way of details about the health of the president, for whom the December operation was the fourth since cancer was first detected in his pelvic area in mid-2011.

Chavez has not been seen in public since he was transported to Caracas from Cuba, where he had been treated since the operation.

The president's worsening health has led to increased speculation that his days in office could be numbered.

Should he step down or die, an election to choose a successor would have to be held within 30 days. Chavez has endorsed Maduro as his preferred successor and opinion polls indicate that he would be the favorite to win an election.

pfd/kms (Reuters, AFP, AP)