After three false starts and several outbreaks of political violence, the government today set June 27 and July 1 and 2 as the dates for Zimbabwe's first general election since independence five years ago.

The announcement, made at a press conference by Minister of Justice Eddison Zvobgo, came amid renewed allegations by Zimbabwe's minority parties that harassment by the government and its followers has made a fair vote impossible. Prime Minister Robert Mugabe is widely expected to retain power, and many analysts expect that he will improve upon the 58-seat majority he now holds in the 100-member Parliament.

Zvobgo announced that the 2.9 million registered black voters will vote July 1 and 2 for candidates to 80 of the parliamentary seats. The 35,000 registered whites, who constitute less than 2 percent of the population yet control more than 20 seats, will vote June 27.

The government is anticipating widespread international attention for what initially was billed as an election in which Mugabe would seek a mandate for one-party rule. In recent weeks, the government has moved away from this formulation and has pledged to do everything in its power to make the balloting fair. Zimbabwe is one of the few African countries claiming to function as a multiparty democracy.

Zvobgo, said opposition parties would have "free and fair access" to state-owned broadcast media and the semiofficial daily press, as well as the freedom to campaign openly throughout the country. For most of the past five years, the local press, television and radio have seldom mentioned opposition figures except when they were under attack from leaders of Mugabe's Zimbabwe African National Union party.

"This is a government pledge," Zvobgo said. "There will be no advantage given or taken from any political party or individuals who wish to contest this election."

But opposition leader Joshua Nkomo, whose Zimbabwe African People's Union party holds 19 parliamentary seats, told a political rally yesterday in the southern city of Bulawayo that the government had arrested some of his field organizers and denied his party permission to hold meetings in some areas and that "agents" of Mugabe's party had broken up other meetings.

Nkomo's allegations gained new weight when police yesterday ordered his supporters to cancel a rally planned for a Harare suburb after a large group of Mugabe's followers descended upon a sports field for which Nkomo's people had a permit. Police said the rally was canceled to avert bloodshed.

The opposition leader, who was leader of a rival guerrilla movement during the war for black-majority rule, also accused Mugabe's government of "tampering" with the electoral process by shortening to one week the legal minimum time allotted for parties to nominate parliamentary candidates and by banning his party's designated symbol, a soaring eagle.

The government used its emergency powers last month to ban Nkomo's symbol, contending it too closely resembled those used by Air Force and police units. Party symbols are of major importance in a country where at least 50 percent of the adult population is illiterate. Nkomo unveiled a new symbol, a charging bull, at yesterday's rally.

Nkomo and other opposition figures, including former prime minister Abel Muzorewa, whose party holds three parliamentary seats, have also charged that halving of the nominations period gives the government unfair advantage.

Mugabe first planned to hold the election last January, then changed the date to March after being informed by advisers it would be impossible to register all likely voters and redraw legislative district lines in time. He said in April that the poll would be in June. But the nonpartisan, four-member commission redrawing the boundaries submitted its report only last week, again forcing the government to set back the date to early July.

The on-again, off-again poll led to mounting violence earlier this year when gangs of pro-Mugabe youths clashed repeatedly with supporters of Nkomo and Muzorewa. At least a dozen persons were killed. In March, the Army sealed off Bulawayo, Nkomo's political stronghold, for two days, temporarily detaining 1,282 persons, while searching house-to-house for weapons in what officials later said was an attempt to quell unrest.