An official with Nigeria's election commission has ruled out a further delay in presidential and parliamentary elections, saying voting will go ahead on Saturday.
Some foreign observers, including Botswana's ex-President Festus Mogae, have raised doubts about whether the commission would be ready for the poll.
The commission announced about five hours before polls were due to open on Saturday that it had postponed the vote by a week, causing shock and anger.
In a BBC Newsday radio interview, Mr Mogae said there was "a great deal of work yet to be done".
"I don’t know whether that can be managed or not. I am not in a position to judge but it makes me apprehensive. I am not sure that it will be done in time," he added.
However, election commissioner Festus Okoye told BBC Newsday: "I don't think the Nigerian people will give us a second chance. On Saturday, Nigerians are going to go to the polls.There is no challenge any more."
Source: bbc.com