The decision to suspend the elections until further notice, announced by the National Electoral Commission, came after the National Republican Convention (NRC) - whose candidate Bashir Tofa was trailing badly in Saturday's poll - accused Chief Abiola's Social Democratic Party (SDP) of massive vote-rigging. A Nigerian court imposed an injunction barring the NEC from publishing any further results. With results from half of Nigeria's 30 states published on Monday, Chief Abiola, 55, was leading Mr Tofa, 45, by a wide margin.
The election winner was scheduled to be inaugurated on 27 August, the day General Ibrahim Babangida has promised to hand over power to an elected civilian president. Gen Babangida has delayed the handover three times before, and many observers, including the former head of state, retired General Olusegun Obasanjo, said they feared a fourth postponement was possible.
Chief Abiola's running mate, Baba Gana Kingibe, was upset by the decision that, at least for now, keeps him from the vice-presidency. 'We did not have court cases,' he said of his party. 'We had an election. There is a result and we are awaiting the announcement.'
'It is obnoxious,' Amos Idakula, a senior SDP official, told reporters in Abuja after the statement. Tokunbo Afikuyomi, an SDP member of Nigeria's house of representatives, said: 'This is a tragedy. It is a total travesty of democracy.'
NEC's decision to obey this latest court injunction contrasted sharply with its rejection last week of a high court ruling ordering it to halt the holding of elections. That order came after a pro-military group, the Association for a Better Nigeria (ABN), brought a case to stop the polls, arguing that civilian politicians were not mature enough to rule the country. The ABN, a shadowy group made up of wealthy businessmen and former politicians, has campaigned for Gen Babangida's eight-year-old military government to stay on for another four years.
The next few days will be critical to maintaining calm, especially in the former capital, Lagos, and neighbouring states, where Chief Abiola, a flamboyant Yoruba Muslim businessman, is regarded as a saviour.
If his victory is confirmed he will become Nigeria's first elected president from the south. Traditionally, civilian presidents come from the country's biggest ethnic group, the Hausa/Fulani people, in the north.
While both candidates have close links with Gen Babangida, most observers regarded Mr Tofa as less likely to bow to public pressure for an investigation into allegations of corruption and mismanagement by the military government.
In recent weeks Chief Abiola had suggested he would scrap Gen Babangida's 'structural adjustment programme' to reform the economy, and he repeatedly laid blame for soaring inflation and the drastic devaluation of the national currency, the naira, at the door of the military.