By Michael Martina

BEIJING (Reuters) - China's President Xi Jinping condemned "cliques", "conspiracies" and "fraud" within upper echelons of the Communist Party and said there were urgent problems to be addressed, state media reported on Wednesday.

Xi is nearly four years into an unprecedented crackdown on corruption which he has said threatens the party's survival. His campaign has brought down scores of senior officials in the party, the government, the military and state-owned enterprises.

"Political life in the party has been good in general terms, but there are also prominent problems which remain in urgent need of addressing," the official Xinhua news agency cited Xi as saying in a speech at the meeting.

These problems include a lack of faith in the party, lax discipline, fraud and corruption, "money worship", nepotism, and a trade in official positions, Xi said.

"Especially an extremely small minority of people among high-level cadres have swelling political ambitions, crave power, pay lip service, form cliques and gangs, and seek power and position and other political conspiracies," Xi said.

He compared China's "political ecology" to environmental ecology, saying that once they are polluted "a great price must be paid to recover them".

Jailed former domestic security chief, Zhou Yongkang, and other fallen senior officials, are examples of the "economic" and "political" problems plaguing the party, he said.

There has been repeated speculation at home and abroad - and sources with ties to the leadership have told Reuters - that President Xi's crackdown is as much about Xi taking down his enemies as it is about cleaning up the party. But Xi has denied any form of power struggle.

The breadth of the expanded campaign has created uncertainty and even fear for some in the party, but it has proved popular with a public fed up with corruption among civil servants.

The speech was released along with the texts of two documents set out at a key party meeting last week, one on party discipline and another on what China calls "intra-Party supervision", intended to ensure its members are clean in the absence of an independent anti-corruption body which the country says it does not need.

At the meeting Xi was named "core" of the party, a title that marks a significant strengthening of Xi's position ahead of an important party congress next year, at which a new Standing Committee, the pinnacle of power in China, will be constituted.

A senior party official, Deng Maosheng, said this week that there must be "flexibility" on age limits for China's top leaders, hinting at a possible shift in party guidelines that could give Xi more leeway in the shuffling of top posts.

Under previously observed age norms, Xi's current anti-corruption tsar Wang Qishan would be too old to begin another Standing Committee term.

(Reporting by Michael Martina; Editing by Raissa Kasolowsky)