Sudan's President Omar al-Bashir, who is wanted for war crimes, will stand largely unopposed in upcoming elections after his main opponents joined an escalating boycott, complaining of fraud and intimidation.
Yesterday's announcement may have wrecked any remaining credibility in the first election to be staged in Africa's largest country since it emerged from the continent's longest civil war.
The unravelling of polls which had been central to the five-year-old peace process will heighten fears of renewed conflict in the vast, oil-rich country which has spent much of the last half century at war.
The withdrawal came despite a late intervention by the US envoy Scott Gration who met yesterday with representatives of the major parties in the capital Khartoum to plead for their continued involvement.
Instead, Sudan's main opposition parties joined a partial boycott that had begun with the surprise withdrawal of Mr Bashir's main challenger, Yasir Arman, from Sudan People's Liberation Movement (SPLM) on Wednesday evening.
The SPLM, which grew out of the decades-long war between the Muslim and Arab-dominated North and the mainly Christian and animist South, pulled out of the voting in Darfur saying it was "impossible" to stage an election there, and withdrew from the presidential poll citing widespread "rigging".
The move represents a serious setback for the international community that pushed for elections to be included in a peace deal signed in 2005 despite little apparent support for them from leaders in either the North or the South. Millions of pounds in international aid has since been spent in setting up Africa's most complicated and ambitious election since the war-torn Democratic Republic of Congo voted in 2006.
Billed as Sudan's first meaningful election in 24 years, the 11 April poll was meant to decide the presidency, national and regional assemblies, local government and representation in the semi-autonomous government of Southern Sudan.
If it goes ahead, it will mean voters – many of whom, in the South particularly, are illiterate – face a bewildering array of candidates to choose from in nearly a dozen different voting categories. Last night it remained unclear whether voting would proceed as planned, while Sudan's complex and shifting political alliances assessed their next moves.
The build-up to the election has exposed the starkly different aims of the parties due to contest the vote. Mr Bashir had been desperate for the vote to take place in some form in order to gain legitimacy as he continues to defy the International Criminal Court which is seeking his arrest on charges of war crimes, crimes against humanity and a possible genocide charge over abuses in the Western region of Darfur.
The SPLM, which enjoys near-total support in the South, is more concerned with a referendum due early next year on secession from the North. Other political groups had hoped to unite the opposition behind a single candidate and defeat Mr Bashir and his National Congress Party.
However, few analysts gave the election much chance of being conducted with anything approaching the "free and fair" mantra of the international community. Human rights groups and international observers have joined local opposition parties in pointing to serious flaws in the campaign and electoral commission. The ruling party is accused of intimidating its opponents, monopolising the media, skewing a census and printing its own ballots.
The abuses led some monitors to call for the vote to be postponed last month which drew a typically furious response from Mr Bashir, who said he would "cut off the fingers" of interfering foreign observers.
Some smaller parties questioned whether a deal had been struck by the Bashir regime and the SPLM in which a partial boycott would hand their leader the presidency in return for an agreement not to stall on next year's referendum on splitting the country.
Sudan has been kept in the headlines by continued interest in the suffering in its Western region of Darfur but the most explosive fault line runs across the country's oil-producing middle. This is where much of the worst of the fighting took place in the decades of civil war and where almost all of Sudan's oil lies. The SPLM-dominated South sees these oil fields as the future engine of the economy in the world's newest country if a referendum is allowed to go ahead next year.
While a flawed election this month could trigger renewed violence, any delays or attempts to block the referendum next year could see a swift resumption of a full-blown civil war.
The Sudan story: A history of strife
National elections were intended to encourage the emergence of democracy after decades of division and violence. Sudan is Africa's biggest country but is split along religious lines and has been in a near constant state of war since independence in 1956. President Omar al-Bashir seized power in a bloodless coup in 1989 after years of unrest sparked by growing Islamisation and feuding over the discovery of oil. He intensified the war against the non-Muslim South. The country's harbouring of Osama bin Laden in the early 1990s led to US air strikes and international isolation. A new front in the civil war opened in Darfur in 2003 when reprisal attacks by government- supported Arab militia left 200,000 dead and two million displaced.