For the first time since he and his brother came to power more than a half century ago, President Raul Castro proposed term limits for Cuba's leaders, admitted that errors have left the country with no obvious successor and promised to rejuvenate the island's political class.
The term-limit proposal made Saturday at the launch of a key Communist Party summit would make it all but impossible for a repeat of the Castros' own political dynasty, which has dominated Cuba since their 1959 revolution. But it would have little practical impact on Raul's future.
The 79-year-old leader officially took over from his brother in 2008, meaning he wouldn't be term-limited out of office until at least 2018, depending on how the law is written.
Castro promised to launch a "systematic rejuvenation" of the government. He said politicians and other important officials should be restricted to two consecutive five-year terms, including "the current president of the Council of State and his ministers" -- a reference to himself.
The proposal was made toward the end of a 2 1/2 hour speech in which the Cuban leader forcefully backed a laundry list of changes to the country's socialist economic system, including the eventual elimination of ration books and other subsidies, the decentralization of the island nation's economy and a new reliance on supply and demand in some sectors.
He said that the party is far along in a study of whether to legalize the sale of cars and homes, which have been all but frozen since the revolution.
Still, Castro drew a line in the Caribbean sand across which the reforms must never go, telling party luminaries that he had rejected dozens of suggested changes that would have allowed the concentration of property in private hands.
Castro said the country had ignored its problems for too long, and made clear Cuba had to make tough decisions if it wanted to survive.
"No country or person can spend more than they have," he said. "Two plus two is four. Never five, much less six or seven -- as we have sometimes pretended."
Delegates to the Congress will be breaking up in committees and meeting behind closed doors on Sunday and Monday, before the Congress closes on Tuesday, presumably with another speech by Castro.
Dressed in a white guayabera shirt, the Cuban leader alternated between reassurances that the economic changes were compatible with socialism, and a brutal assessment of the mistakes the country had made.
Castro said the monthly ration book of basic foods, perhaps the most cherished of subsidies, represented an "unbearable burden ... and a disincentive for work."
He said the changes he is proposing will come "without hurry, but without pause."
Still, he added that "there will never be room for shock therapy" in Cuba.
Of term limits, Castro said he and his brother had made various attempts to promote young leaders, but that they had not worked out well -- perhaps a reference to the 2009 firing of Cuba's photogenic foreign minister and vice president, who were later accused of lusting too obviously for power.
"Today we face the consequences of not having a reserve of substitutes ready," Castro said.
Along with the proposals on economic changes, the term-limit idea does not yet carry the force of law since the party gathering lacks the powers of parliament. But it's all but certain to be acted on quickly by the National Assembly.
The Communist Party is the only political organization recognized on the island, and most politicians are members. Cubans vote for municipal and national assemblies, which in turn elect senior leaders including the president. Currently there is no set limit on their terms.
Since taking office, Raul Castro has leased tens of thousands of hectares of fallow government land to small farmers, and enacted reforms that allow Cubans to go into business for themselves, rent out homes and hire employees.
Cubans are watching to see whether other changes emerge from the Congress -- such as the end of a near-total ban on buying and selling private property, or details on promises to extend bank credits.
The other major prong of the modernization drive -- a goal of laying off half a million state workers in jobs that are unproductive and redundant -- has been delayed indefinitely.
Another key task of the Congress is to select a new Communist Party leadership. Raul Castro presumably will be named to succeed older brother Fidel as first secretary, but it is unknown who will be tapped to be No. 2.
Castro's speech about rejuvenating the political system added to hopes that a younger politician might take up that mantle, perhaps signaling a preferred successor.
"If there's any changes in leadership, especially any promotion of someone from the younger generation, that would give a hint as to who might be a possible future president," said Philip Peters, a Cuba specialist who is vice president of the Arlington, Virginia-based Lexington Institute.
The Associated Press contributed to this story.