JOHANNESBURG -- Zimbabwe's next election will be held on July 31, the country's longtime president, Robert G. Mugabe, announced in a presidential decree on Thursday, setting up a showdown with the main opposition party over whether credible elections can be organized in just six weeks.
The truncated timetable raises new fears that the election will be a repeat of the disastrous 2008 vote, in which Morgan Tsvangirai, the main opposition candidate, won the most votes, but refused to participate in a runoff because of violence by the country's security forces that targeted his supporters.
Regional powers brokered an agreement that put Mr. Mugabe, who has ruled the country since it won independence from Britain in 1980, into an uneasy power-sharing government with his rival, Mr. Tsvangirai, who was named prime minister. The unity government was meant to oversee comprehensive reforms to the state security apparatus and Zimbabwe's electoral laws and to write a new constitution. Only the last of these three tasks has been completed.
An angry Mr. Tsvangirai told reporters in Harare, Zimbabwe's capital, that Mr. Mugabe had no right to set the election date by presidential decree.
"As prime minister, I cannot and will not accept this," Mr. Tsvangirai said. "Mugabe is deliberately precipitating a constitutional crisis."
Zimbabwe's highest court ruled on May 31 that the elections must be held by the end of July despite the fact that key electoral reforms, like making a new voter roll and reforming the election commission, had not been completed. At the time, the main opposition party, the Movement for Democratic Change, criticized the decision, saying that the court had no right to set election dates.
In a letter addressed to Mr. Tsvangirai, Mr. Mugabe wrote that "it became inexpedient" to wait for Parliament to pass the electoral reform laws necessary to bring current law into line with the new constitution. Mr. Mugabe's government had already announced that it planned to bar Western election observers from monitoring the vot.
Trevor Maisiri, an analyst at the International Crisis Group, said that without major reforms, it would be very hard to hold a fair election in such a tense country on such a short timetable.
"Given the outstanding issues it is difficult to imagine having a credible process at the end of the day," Mr. Maisiri said.
The leaders of Zimbabwe's neighboring countries will gather on Saturday in Mozambique at a summit meeting of the Southern African Development Community, a regional trading bloc, and Zimbabwe's elections are expected to be at the top of the agenda.
Because of the top court's ruling, the opposition has no legal recourse within Zimbabwe and is likely to plead its case to regional leaders, urging delay. South Africa in particular is eager to avoid another violent election, because unrest in Zimbabwe inevitably sends refugees fleeing over the Limpopo River into South Africa.
"Mugabe has taken a very calculated decision by going to the S.A.D.C. meeting with the election date set," Mr. Maisiri said. "Now the issue will be, 'What can we offer Mugabe to climb down from his position?' " That could result in a serious watering down of the reforms demanded under the terms of the unity government and the new constitution, he said.
In a report released earlier this month, Human Rights Watch said that failing to reform the country's army and police forces would spell disaster at election time.
"There is an urgent need, ahead of the elections, for Zimbabwe's security forces to be drastically reformed, to create a political environment conducive for holding nonviolent and credible elections," the report said.
The fight over the election date comes as Zimbabwe is slowly emerging from its paraiah status. In March, the European Union suspended its longstanding sanctions on all but 10 top officials in Zimbabwe, citing the successful referendum on the new constitution.
Earlier this month, the International Monetary Fund took the first steps toward normalizing its relationship with Zimbabwe after more than a decade. The fund agreed to a fiscal monitoring program that could pave the way to clearing billions of dollars in arrears Zimbabwe owes.
This article originally appeared in The New York Times.