Nigeria's President Olusegun Obasanjo says his party accepts the Senate's rejection of a bill that would have allowed him to seek a third term.
Mr Obasanjo said he had been maligned in the press
He said the People's Democratic Party needed to put the acrimony behind it and prepare for next year's election as the constitution currently stands.
Confirmation that Mr Obasanjo will not stand again leaves Vice-President Atiku Abubakar as a strong candidate.
The two fell out over the issue that also deeply divided the country.
Two former military rulers, Ibrahim Babangida and Muhammadu Buhari, have also emerged as likely candidates.
"As a political party, we should accept the verdict of the National Assembly even though the two chambers initially concluded differently," the president told PDP delegates.
The dramatic announcement that the bill had been defeated was greeted with shouts of joy in the Senate on Tuesday.
"The constitution must be held hallowed and sacred. And, on the basis of the constitution in hand, we must start to plan for the next elections," he said.
Mr Obasanjo has never publicly said he wanted to stand for re-election saying he would make his decision if the constitution was amended.
In his speech he hit out at the media for unfounded speculation on the subject.
"Many derogatory statements and unfounded allegations have been made about me and my position concerning the so-called third term... I was maligned, insulted and wrongly accused but I remained where I am and what I am and I remained focused," he said.
President Obasanjo said it was now time to heal the wounds caused by weeks of angry debate on the issue and he criticised both sides for using blackmail, intimidation and violence in their campaigns.
Those opposed to changing the constitution had claimed that they had been offered bribes and threatened to change their minds.
Nigeria had many years of military rule until Mr Obasanjo was elected in 1999.
Mr Obasanjo is a Christian from the south-west and people in other parts of the country believe the country's top job should rotate between the regions.
Mr Abubakar is a northern Muslim, like another man seen as a strong candidate, former military ruler Gen Babangida.
Many prominent members of the PDP have already formed a new political party, the Advanced Congress of Democrats, rumoured to be sponsored by Mr Abubakar, and he was a notable absentee at the PDP meeting.
The BBC's Alex Last in Lagos says many in the oil-producing south and the south-east - regions which have never produced a Nigerian president - feel it should be their turn.
But our correspondent says winning elections in Nigeria is largely about who has got the most power and money behind them.