By Jeff Franks and Rosa Tania Valdes
HAVANA (Reuters) - Cubans mostly welcomed President Raul Castro's call at a Communist Party congress this weekend to limit the terms of island leaders, saying on Sunday it would bring new blood to the government the Castros and their aging colleagues have ruled for 52 years.
The 79-year-old president told 1,000 delegates at the start of the four-day congress on Saturday that limiting high political and state positions to two five-year terms would help "guarantee the systematic rejuvenation" of leadership.
It was not possible to do this before because present circumstances are "quite different from those prevailing in the first decades of the revolution that was not yet consolidated when it had already become the target of continuous threats and aggressions."
The matter would not be taken up now, Castro said, but at a party conference in January. He said any limits would apply to him as well.
Retired worker Cristina Mesa, 77, said Cuban leaders, most of whom are in their 70s and 80s, had finally recognized what others have seen for a long time.
"It is very clear that the country has to give way to the young people and it has to trust them, there's no other choice," she said.
"The limit is an efficient way of preventing anyone from believing they can hold on forever to a post. If they govern well, they stay, if not, they go and that has to be decided by the people."
Student Laritza Martinez said the proposal came as a surprise because the Castro brothers have been constants in Cuban life since taking power in the 1959 revolution they led.
Fidel Castro, who is 84 and did not attend the congress, ruled for 49 years, while younger brother Raul Castro was defense minister during the same time before taking over the presidency in 2008.
NOTHING IS PERFECT
"I didn't expect to hear that. It's fantastic that in politics we'll be able to be like the rest of the world," Martinez said. "Nothing is perfect, but it appears that Raul really wants to modernize the country."
Skeptics said they believed Raul Castro's motives were less about assuring that future leadership will not become entrenched than about giving the false impression current leaders are not trying to hold on to power for as long as possible.
"They're proposing this now because they know it won't affect them," said plumber Angel Garrido. "I think they plan to stay in office until they die."
Laura Pollan, leader of the dissident group Ladies in White, said: "What they are doing is this -- winning time to stay in power. This a cancer that is now in its final stages."
Cuba's aging leadership is a concern for a government intent on assuring the survival of Cuban socialism after current bosses are gone.
President Castro said they are facing "the consequences of not having a reserve of well-trained replacements" to take over.
Currently in the line of succession are first vice president Juan Machado Ventura, 80, and second vice president Ramiro Valdes, who is 77.
The party congress' two main tasks are to approve 311 proposed reforms to Cuba's creaking, Soviet-style economy to make it viable for the future and to elect party leadership.
Raul Castro is expected to be elected first secretary, officially replacing Fidel Castro, who said last month he had resigned the post without making it public when he fell ill in 2006. Raul Castro has taken over his duties, but is officially second secretary.
The congress will elect a new second secretary, the Central Committee and Political Bureau. All will be watched closely for possible new leaders.
This congress, which has been delayed several times and is the first in 14 years, is considered the most important since the party's first in 1975 when it adopted the Soviet-style system.
Its meeting on Sunday was being held in private, with no foreign press allowed in.
Sunday's session fell on the 50th anniversary of the U.S.-backed Bay of Pigs invasion, a failed attempt to start a counter-revolution against Fidel Castro. It was marked on Saturday with a military parade through Havana's Revolution Square.
(Editing by Mohammad Zargham)