Prime Minister Robert Mugabe issued a tough new warning today to his political opponents to submit to his rule following his governing party's landslide victory in Zimbabwe's first parliamentary election since independence.

Mugabe said at a press conference that his party's triumph was a popular mandate to move Zimbabwe more rapidly toward a one-party state and to abolish the special whites-only vote that last week gave one of his bitterest political foes, former prime minister Ian Smith, 15 seats in the new Parliament.

He said that whites who objected to his policies should leave the country and that western critics of his plans to rewrite Zimbabwe's constitution to eliminate opposition parties and the white voters' roll could "go hang."

Mugabe's Zimbabwe African National Union won 63 seats to 15 for opposition leader Joshua Nkomo's party and one for a minority candidate in final results announced today. But his triumph still leaves the nation deeply divided along racial and tribal lines.

Mugabe's party gained six seats in Parliament and swept every region except southwestern Matabeleland, Nkomo's political stronghold.

The victory ensures Mugabe a second five-year term as prime minister. After a by-election in a few weeks to fill one remaining seat, his party is expected to hold 64 seats in the 100-member Parliament.

Mugabe also consolidated his hold over Zimbabwe's Shona-speaking majority, eliminating from Parliament his main Shona rival, Methodist Bishop Abel Muzorewa. Mugabe's party now holds all but one Shona-dominated seat. The remaining seat was won by a supporter of his exiled political rival, the Rev. Ndabaningi Sithole.

Five years ago following the pre-independence parliamentary election, Mugabe used his upset triumph as a platform to preach reconciliation between blacks and whites and between Nkomo's supporters and his own. Today, however, fresh from his new victory, he warned that those who refused to unite under the "political umbrella" of his ruling party would face unrelenting hostility from the government.

"We have to ensure that our society is rid of those undesirable elements whose own attitudes militate against the attainment of unity," he said at a press conference this afternoon.

He included in that category the whites who voted for Smith last week.

"Those whites who have not accepted the reality of a political order in which the Africans set the pace have to leave the country," Mugabe warned.

He also castigated Nkomo's party, saying it was responsible for continuing unrest in Matabeleland because it "sponsored" armed dissidents there who had murdered government supporters.

Mugabe said Matabeleland voters had supported Nkomo out of fear and said he would continue the government's harsh counterinsurgency campaign against dissidents. Hundreds of civilians have died in Army operations in the region during the past three years.

The people of Matabeleland, Mugabe said, "are not a foreign element. They are part and parcel of our population. We are satisfied ourselves that without Nkomo, without the dissident element, they will fall in line."

Nkomo, who consistently has denied any connection between his party and the dissidents, today said the racial and tribal divisions reflected in the election result were tragic.

"Something has got to be done to bring the people together and end this national tragedy," Nkomo told the state-run news agency Ziana in an interview. "You cannot force it, you have to solve it."

Mugabe said he would move "almost immediately" to amend Zimbabwe's constitution to abolish the special white voters' roll and oust Smith and his followers from Parliament. But he stopped short of committing himself to taking action outside the provisions of the constitution, which states that the white roll cannot be eliminated without a unanimous parliamentary vote until at least 1987.

Whites make up less than 2 percent of the population of Zimbabwe.

Mugabe also indicated his impatience with the constitutional clause that prevents adoption of a one-party state until at least 1990.

The election results offer the possibility of a parliamentary alliance between Smith and Nkomo. Together, they and the white independents have enough votes to thwart any move to abolish the white roll in 1987. Under Zimbabwe's constitution, Mugabe will then need 70 votes to eliminate the roll.

The constitution was formulated in 1979 at a summit meeting in London as a prelude to black majority rule. Among those who participated were Smith, Mugabe and Nkomo. All parties committed themselves to honoring the document, which gave special voting privileges to whites to reassure them that they would not be overwhelmed by a black government.

Mugabe said today that he had accepted the constitution despite the fact that he found "certain features" objectionable. But he said the document had ceased to represent the will of Zimbabwe's black majority.

"The American constitution I don't think emanated from London," he said. "It was a creation of the people of the United States, and the people of Zimbabwe can create their own constitution as well."