By Ben Blanchard and Chris Buckley
BEIJING (Reuters) - China's ruling Communist Party must ensure economic growth and its iron grip on stability do not slacken, President Hu Jintao said on Friday, using the party's 90th anniversary as a show of unity ahead of a tricky leadership succession.
"Development is of paramount importance and stability is the paramount task," Hu told hand-picked party members inside Beijing's cavernous Great Hall of the People, in a speech carried live on state television.
"Without stability, nothing can be accomplished, and the achievements that we have made will be lost. All of the party's comrade's must take this message to heart, and they must also lead all the people to take this to heart," he said.
"Only by promoting both healthy and fast economic development can we secure a strong material foundation for the great revival of the Chinese nation."
The party has shown no sign of diluting its own vast powers before a big political shake-up late next year, when Hu will hand over power, most likely to Vice President Xi Jinping.
Xi gave a short introductory address before Hu took the stage, to congratulate model party members.
Hu's predecessor, Jiang Zemin, did not attend the ceremony, possibly a sign of the 84-year-old's declining health. Hu, aged 68, is also beginning to show his age, despite the jet-black head of hair that all central leaders sport, thanks to dye.
China launched a wave of propaganda in the weeks leading up to the anniversary, producing slick films and decking out Beijing with banners lauding party rule and the progress the country has made since the 1949 revolution.
While Premier Wen Jiabao, who is also preparing to retire, has made a habit recently of more directly calling for political reform than his more cautious comrades, the party appears in no mood to listen.
"Looking back at the progress that China has made over 90 years, we can reach one fundamental conclusion -- that the key to properly managing China's affairs lies in the party," said Hu, who oversees the world's largest political party, with 80 million members.
"We have every reason to be proud of what the party and the people have achieved, but we have no reason to be complacent. We must not and will never rest on our laurels."
Yet despite some oblique sniping between provincial leaders vying for a place in the next central leadership, Hu has presided over a strikingly disciplined group of top leaders, said Kerry Brown, head of the Asia Programme at Chatham House, a London foreign policy institute.
"Some pundits try to create a drama, when in fact the most interesting thing is the absolute, icy stillness at the center," said Brown, who is writing a biography of Hu.
"With the things that are going on, and all of the problems, there must be pretty passionate debates, but we don't get a sign of it," he said in a telephone interview.
"CONFLICTS AND PROBLEMS"
After some muted moves to give citizens stronger legal protections early in his time as president, Hu has made enforcing firmer control over China's increasingly diverse and fractious society a feature of his time in power.
The last few months have been marked by arrests and detentions of dissidents, human rights lawyers and long-time protesters, following calls online for Arab-style "Jasmine protests" in China.
Hu warned about the strains buffeting party rule as the consequences of economic transformation courses through Chinese society.
"Currently China is undergoing an unprecedentedly broad social transformation. At the same time as bringing tremendous vitality to our country's development and progress, this will also inevitably bring all kinds of conflicts and problems."
Despite China's robust economic growth, its communist leaders worry that their rule could be eroded and eventually challenged by social unrest and elite schisms and send it the way of the Soviet Union which collapsed two decade ago.
The country saw almost 90,000 "mass incidents" -- riots, protests, mass petitions and other acts of unrest -- in 2009, according to a 2011 study by two scholars from Nankai University in north China. Some estimates go even higher.
By contrast, in 2007, China had more than 80,000 mass incidents, up from over 60,000 in 2006, according to an earlier report from the Chinese Academy of Social Sciences.
"The whole party must see with crystal clarity that the conditions facing the world, the country and party are undergoing profound changes, and that under these new circumstances we face unprecedented new circumstances and challenges," Hu said.
(Additional reporting by K.J. Kwon; Editing by Alex Richardson)