More than 800 politicians and high-ranking officials were banned from South Korea's political life for the next seven years and eight months today in a sweeping purge that eliminated most opposition to the new military-based government.

A nine-man screening committee, announcing the list of 811 barred from political activities, said it acted to put an end to the existing political order and open a new era of fresh politics. Its action virtually ruled out competition against President Chun Doo Hwan by foes who otherwise might have run against him in the forthcoming presidential election.

"The committee has conducted the fair screening under the basic principle to punish those who were conspicuously responsible for political and social confusion during the old era and to form a political order suitable for a new era," a statement said.

Prominent figures on the ban list include Kim Chong Pil, president of the Democratic Republican Party; Kim Young Sam, president of the New Democratic Party; Kim Dae Jung, former National Democratic Party presidential candidate who is awaiting a Supreme Court decision on his death sentence; and Chung II Kwon and Paik Too Chin, former speakers of the National Assembly.

In a move to make the political vacuum as short as possible, the 81-man Legislative Council for National Security, in accordance with provisions of the new constitution, has been working on legislating various political laws. Political observers said political activities by new faces will be resumed early next month as soon as the legislative council enacts a political party law, a political funding law and an election management law.

Political acvitity has been banned in South Korea since May 17 this year when the government imposed martial law. As the new constitution went into force last month, all political parties have been disbanded since Oct. 27.

Reliable sources said at least four new political parties will be organized. A number of military officers, including some generals, have been making preparations for taking off their uniforms to take over key posts in a government party, the sources added.

Chun, the general-turned-president, has pledged that a presidential election through an electoral college will be held next March and that National Assembly elections will be held in April or May.

In announcing today's bans, the Political Renovation Committee headed by Supreme Court Justice Kim Chung Soh said it screened 7,066 persons. The list of those banned includes 210 former national assemblymen, 254 key members of political, parties and 347 others who have been accused of being responsible for political and social corruption and irregularities.

Since its first republic was established in 1948, this is the fourth time South Korea has used political banning lists. But the current package differs from its predecessors in many respects and appears to be considerably more for reaching.

The defunct Political Reform Law enacted by the late president Park Chung Hee following a military revolution in 1961 listed 4,300 politicians for screening, but only 269 suffered the political ban for six years. The current political ban is more stringent and unchangeable, although those listed can appeal their cases.

The first political purge was enacted in August 1948 castigating Koreans who had actively collaborated with the Japanese during their occupation from 1910 to 1945. At the time, the political law provided for penalties ranging from death sentence to 10 years in prison for those who cooperated with Japanese and who either killed or persecuted Korean patriots or their families.

The second law, enacted in December 1960, was designed to suspend the franchise of core members of the Liberal Party of the late president Syngman Rhee involved in rigging elections. The Syngman Rhee government had been toppled by a student revolution in April 1960.