By Mario Naranjo and Marianna Parraga
CARACAS (Reuters) - A military comrade of Hugo Chavez who was once Venezuela's president for a day has become his most powerful ally at a delicate time when the socialist leader is seeking re-election despite cancer.
The rise of Diosdado Cabello, 48, has coincided with Chavez's latest convalescence from surgery and has set tongues wagging that he could be the chosen one as successor should the president's health deteriorate.
To the envy of other senior "Chavistas", the burly army lieutenant who is second only to Chavez in the ruling Socialist Party was also named early this year as the head of parliament.
During Chavez's recent three-week absence in Cuba for the removal of a second malignant tumor, Cabello fronted government news conferences and led rallies. Then he stood proudly next to the president on the palace balcony at a weekend homecoming.
"He has taken on a protagonistic role. That was the president's intention," said one former minister and government ally, asking not to be named due to the delicate subject.
Just how protagonistic remains to be seen: Chavez frequently shuffles his top aides and eschews all talk of succession.
Yet Cabello's rise has clearly eclipsed two other heavyweights - Vice President Elias Jaua and Foreign Minister Nicolas Maduro - whom Venezuelans had last year been speculating were equally strong-looking contenders to replace Chavez.
Both are being sent to the provinces later this year to campaign for Chavez in the October 7 presidential vote and then contend state governorships. Analysts interpret that as a snub to any presidential ambitions they may have privately harbored.
"Elias carries out the day-to-day business, while Diosdado is the mover of the masses," the ex-minister added, describing Chavez's roles for them.
In public, Cabello certainly shows more charisma and more of a popular touch than other top officials, though still a long way from Chavez's own famous "connection" with the masses.
Unusually, the crowd at one recent rally ventured to cheer "Viva Diosdado!" along with "Viva Chavez!"
PRESIDENT FOR A DAY
Though many locals see Cabello as the man-in-waiting if Chavez succumbs to cancer, Cabello is the first to deny that.
"The candidate for the Bolivarian Revolution is called Hugo Chavez Frias! The only one who guarantees stability in this country is Hugo Chavez Frias!" he has bellowed over-and-over.
Skeptics say that public line belies huge anxiety within the Socialist Party about Chavez's health and future, and a nascent power struggle between the senior figures around him.
Chavez insists he is recovering from the removal of a second tumor in his pelvis, but he still needs radiation treatment. That will leave him weakened during the campaign and there are rumors that his condition is life-threatening.
Having joined Chavez's abortive military coup in 1992, served time in jail alongside him as a result, and then helped steer his successful 1998 election campaign, Cabello's star has waxed and waned during his boss's 13-year rule.
In the ministerial merry-go-round that Chavez favors to keep everybody on their toes, Cabello has served as vice president, led five ministries and had a handful of other important posts in government. His brother has also held high offices.
At some points, Chavez has none-too-subtly relegated Cabello when he seemed to be becoming too big for his boots.
One of the world's shortest-lived presidents, Cabello even held the top job for a turbulent day in 2002.
As a brief coup against Chavez collapsed, Cabello stepped in and his only act as president was to send commandos to bring Chavez back from captivity on an island naval base and restore him to power.
Seen as a pragmatist rather than ideologue, Cabello has sway with the military and lawmakers plus close links to businessmen.
"But the grassroots revolutionaries don't trust him," said George Cicciarello-Maher, a U.S. university professor and author of a book on the Chavez government.
Bringing him to the fore now may be Chavez's way of covering his bases before the October 7 vote - the military could be needed if the result is disputed or there is violence on the streets - rather than necessarily positioning Cabello as his dauphin.
"They say Diosdado is the president's favorite right now, but I'm not sure. I've also heard some bad things about him, that he's a bit full of himself," said Juan Vazquez, a 26-year-old workman and Chavez supporter in the western town of Cabimas.
The opposition's presidential candidate, Henrique Capriles, humbled Cabello by beating him in a 2008 election for the Miranda state governorship. Capriles' team say they uncovered a mass of irregularities by Cabellos' outgoing administration.
"They even took the light bulbs from the office. They didn't leave a thing!" Capriles told Reuters.
Cabello denies corruption accusations and the government has been silent on allegations against him - none of which have resulted in charges being brought.
"They call us thieves, dirty, badly-dressed," Cabello told a crowd this month, denouncing the opposition's attitude to him and to "Chavistas" in general. "But they can't do anything against the dignity of the people alongside Comandante Chavez."
The president has a healthy lead over Capriles in recent opinion polls - but the surveys also show Capriles would beat any of the president's allies should they end up running instead of him.
In addition to his new high profile, the pugnacious Cabello has delighted in leading the government's attacks on Capriles, calling him "the candidate of the bourgeoisie" and joking that he was as bland as "an egg without salt."
While Chavez was recovering in hospital in Havana, Cabello also settled an old score with a state governor who had long been hostile to him, helping ensure the governor's suspension from the Socialist Party for "disobedience."
"Diosdado is on the rise and full steam ahead," said one source close to Cabello. "Although Chavez has clipped his wings in the past, now it's much more difficult."
The consensus among analysts is that Chavez will do everything he can to avoid naming a successor or alternative candidate for the October election, because he knows the government's hold on power relies largely on his own popularity.
(Additional reporting by Andrew Cawthorne and Diego Ore; Writing by Andrew Cawthorne; Editing by Daniel Wallis and Kieran Murray)