CARACAS, Venezuela -- Nothing shows the extent of Hugo Chavez's grip on power quite as clearly as his absence from his own inauguration on Thursday.

Venezuela gathered foreign allies and tens of thousands of exuberant supporters Thursday to celebrate a new term for a leader too ill to return home for a real swearing in.

In many ways, it looked like the sort of rally the president has staged scores of times throughout his 14 years in power: The leader's face beamed from shirts, signs and banners. Adoring followers danced and chanted in the streets to music blaring from speakers mounted on trucks. Nearly everyone wore red, the colour of his Bolivarian Revolution movement, as the swelling crowd spilled from the main avenue onto side streets.

But this time, there was no Chavez on the balcony of Miraflores Palace.

It was the first time in Venezuela's history that a president has missed his inauguration, said Elias Pino Iturrieta, a prominent historian. As for the symbolic street rally, Pino said, "perhaps it's the first chapter of what they call Chavismo without Chavez."

Yet in the crowd outside the presidential palace, many insisted that Chavez was still present in their hearts, testifying to his success in forging a tight bond of identity with millions of poor Venezuelans.

The crowd chanted: "We are all Chavez!" Some wore paper cutouts of the yellow, blue and red presidential sash to show they were symbolically swearing in themselves in, in Chavez's place.

"A historic period of this second decade of the 21st century is starting, with our commander leading," said Vice-President Nicolas Maduro, Chavez's designated successor.

The Venezuelan leader, normally at the centre of national attention, is so ill following a fourth cancer surgery in Cuba that he has made no broadcast statement in more than a month, has not appeared in a single photo. Officials have not specified what sort of cancer he suffers or which hospital is treating him.

Yet the opposition, limping off of two recent electoral defeats, seems powerless to effectively challenge him, and critics see their impotence in the battle over his new inauguration as an example of how the president has been able to ignore the constitution at whim.

Despite opposition claims that the constitution demands a Jan. 10 inauguration, the pro-Chavez congress approved delaying the inauguration and the Supreme Court on Wednesday endorsed the postponement, saying the president could be sworn in before the court at a later date.

Opposition lawmaker Maria Corina Machado called that a "well-aimed coup against the Venezuelan Constitution" and echoed other critics' suspicions that foreign allies are influencing events in Venezuela: "It's being directed from Cuba, and by Cubans," she told The Associated Press.

Opposition leaders called for protests on Jan. 23, the anniversary of the of the country's last dictatorship in 1958.

But it is unclear how much support the opposition's complaints can generate amid an outpouring of public sympathy for the ailing president, and with Latin American neighbours either supporting the government's stance or reluctant to step into Venezuela's domestic affairs.

The government invited foreign leaders to add political weight to Thursday's event, and they filled a stage in front of the presidential palace as Maduro addressed the crowd and called it a "historic event."

A recording of Chavez singing the national anthem suddenly appeared, and his followers sang along. At the end, his voice boomed: "Long live the Bolivarian Revolution!"

Sitting beside Maduro were presidents including Daniel Ortega of Nicaragua, Evo Morales of Bolivia and Jose Mujica of Uruguay. The government said officials from about 20 other nations were on hand, including allies from a left-leaning bloc and others participating in a Chavez-launched program that supplies Venezuelan fuel under preferential terms.

Argentine Foreign Minister Hector Timerman said that President Cristina Fernandez was travelling to Havana on Thursday "to be together tomorrow with our friend Hugo Chavez and express all our affection and support."

While the visiting leaders spoke in praise of Chavez, fighter jets thundered overhead, flying low. Members of the Cabinet waved to them, and the crowd went wild waving flags. One of the warplanes did a roll.

Militia troops in fatigues stood in formation. Soldiers and police guarded street corners while hip-hop artists performed in the morning on stages set up along the avenue leading toward the presidential palace.

The mood was festive as Chavez's followers blew horns and held up posters reading: "Now with Chavez more than ever."

Many said they're holding out hope that the president might be able to return home alive eventually, though they also acknowledged he appears to face a difficult struggle.

"We came to show support, so he knows his nation is with him," said Anny Marquez, a secretary and voluntary member of a civilian militia that Chavez has built in recent years. "We're with him in the good times as well as the bad."

It was one of the largest rallies for Chavez in recent years. Public employees joined the president's supporters, and some arrived in government buses after travelling for hours across the country.

Chavez has undergone repeated surgeries, chemotherapy and radiation treatments since June 2011 for an unspecified type of pelvic cancer. The government said in its last update on Monday that Chavez was in a "stable situation" while being treated for a severe respiratory infection.

Many in the crowd said they're praying for the president. Some wore felt hearts in the colours of Venezuela's flag pinned to their shirts, with pictures of Chavez pasted atop the hearts.

Yet even as Chavez's followers projected confidence in the resilience of their socialist movement, some acknowledged the possibility of changes ahead.

"Unfortunately Chavez can't be with us today," said teacher Marcelo Villegas. "But we the people represent Chavez. He is and always will be our leader."