BEIJING — During a holiday banquet for China’s military leadership early this year, a powerful general lashed out in a drunken rage against what he believed was a backhanded move to keep him from being promoted to the military’s top ruling body.


The general, Zhang Qinsheng, vented his fury in front of President Hu Jintao, according to four people with knowledge of the event. At the banquet, he even shoved a commanding general making toasts; Mr. Hu walked out in disgust.


The general’s tirade was one of a series of events this year that have fueled concerns among Communist Party leaders over the level of control they exercise over military officials, who are growing more outspoken and desire greater influence over policy and politics.


With China’s once-a-decade leadership transition only months away, the party is pushing back with a highly visible campaign against disloyalty and corruption, even requiring all officers to report financial assets.


“Party authorities have come to realize that the military is encroaching on political affairs,” said one political scientist with high-level party ties. “Although the party controls the gun, the expression of viewpoints from within the military on political issues has aroused a high level of alarm.” He, like others who agreed to discuss internal party affairs, spoke on the condition of anonymity because of fear of reprisals.


Some generals and admirals have loudly called for the government to assert control over the South China Sea, the focus of increasingly rancorous territorial disputes between several Southeast Asian countries and China, where nationalist spirits are on the rise among the public and politicians as well. And earlier this year, leaders in Beijing became alarmed over ties between generals and the disgraced Politburo member Bo Xilai.


The party’s need to maintain stable rule over an increasingly vocal military is one reason Mr. Hu, its top civilian leader, is expected to hold on to his position as chairman of the Central Military Commission for up to two years after he gives up his party chief title in the fall, according to people briefed on political discussions. His anointed successor, Xi Jinping, would still take over Mr. Hu’s posts as head of the party and head of state, but would have to wait to become China’s military boss.


Mr. Hu’s two predecessors both exercised control of the military after they gave up their other civilian titles. But some party insiders have argued that a staggered handover can lead to rival centers of power, splitting generals’ loyalties. No final decision has been made on whether Mr. Hu will stay on. But if he does, then Mr. Xi could find himself with limited room to expand his power base, even though he has more of a military background than Mr. Hu.


Mr. Hu has been building a network of army loyalists by promoting generals in waves. At least 45 officers have been promoted to full general by Mr. Hu since September 2004, when he became head of the military commission. Just over half the promotions have taken place since July 2010. Four of the 45 are now among the 10 generals who sit on the commission. One officer who rose quickly with Mr. Hu’s support was General Zhang, who could still be in contention for a commission seat despite his drunken tantrum.


When Mr. Hu’s predecessor, Jiang Zemin, held on to his military post from 2002 to 2004, factional enmity arose over many issues. The same could happen with Mr. Hu and Mr. Xi, who was promoted to a vice chairmanship of the military commission in 2010. Mr. Jiang yielded his post to Mr. Hu only after conflicts between the two had intensified.


“The way it goes in the military is: whoever promotes me is my daddy,” said one member of the party elite who meets with generals regularly.


Such divisions need not be debilitating in an increasingly professional military, analysts say.


“They prefer to work out these differences in a consensus-building process,” said Dennis J. Blasko, a retired United States Army intelligence officer and former military attaché at the American Embassy in Beijing. “I see the P.L.A. leadership as rational, pragmatic and realistic,” he added, referring to the People’s Liberation Army.


Nonetheless, conversations with officers suggest that some may feel an affinity for the incoming Mr. Xi they do not share with Mr. Hu, a tea trader’s son who has struggled in Mr. Jiang’s shadow to win respect. Mr. Xi, 59, is the “princeling” son of a revered Communist guerrilla leader who grew up in Beijing with military families. He is stepping into the leadership role with closer military relationships than anyone since Deng Xiaoping.


“When those from the ‘red second generation’ move up, there will be a personal feeling, a traditional bond,” a senior officer said.