BEIJING (Reuters) - China's ruling Communist Party has issued new rules to push its fight against deeply entrenched corruption, telling senior officials to travel "without pomp", not to have too many staff and not take too many holidays.

President Xi Jinping has waged war against graft since assuming office four years ago, warning, like others before him, that the problem is so severe it could weaken the party's grip on power.

The party has already cracked down on what it terms extravagance, hedonism and bureaucratism. The new rules, issued late on Wednesday, further formalize practices and guidelines already generally in effect.

Top officials should "travel without pomp, minimize impact on public life, and not have vehicles exceeding the set standards", say the rules, which were released by the official Xinhua news agency.

Holidays should be limited and properly approved, the "right" number of staff should be employed, relatives and employees must be "strictly constrained" and top officials should not delay leaving their offices on retirement, the rules state.

The Politburo, one of the party's elite ruling bodies headed by Xi, would be the first to follow the rules, and Xi himself is leading by example, Xinhua said.

"To forge an iron, one must be strong oneself," it said.

"Whatever you demand others do, you should first do yourself; whatever you forbid others to do, you should firmly forbid to yourself," it said.

Government departments should now draft detailed plans to implement the new rules and strengthen supervision, which should be implemented without compromise, it said.

China does not have an independent anti-corruption body and insists the party and the government can police themselves.

Xi's crackdown on corruption has moved in recent months away from high-profile officials to weeding out daily corruption at the grass roots, making almost anyone a potential target.

The drive for a clean party, referred to in official documents as "intra-party supervision", was the focus of a four-day meeting of senior party officials in Beijing in October, which concluded by anointing Xi as "core" leader of the party.

On Wednesday, the party also adopted measures on what it refers to as "democratic life" to ensure officials have the "correct political consciousness".

The measures have important meaning for "guiding members and party leaders to firmly establishing political, overall and core consciousness", Xinhua said.

"Authorities should organize 2016 annual democratic life meetings to analyze party members' integrity by criteria such as loyalty, honesty, frugality and whether they insist on seeking truth from facts," it added.

(Reporting by Ben Blanchard; Editing by Paul Tait)