Two former bitter political rivals in Kenya facing trial at the International Criminal Court, Uhuru Kenyatta and William Ruto, are negotiating an alliance for next year's election.
But a statement from Mr Uhuru's office backtracked on an earlier announcement that a deal had been officially agreed.
On Thursday, a court in Kenya is due to hear a petition seeking to bar them from contesting the election.
Both men deny playing key roles in the violence which followed the 2007 poll.
Some 1,200 people were killed and 300,000 forced from their homes.
Deputy Prime Minister Kenyatta and Mr Ruto, a former minister, were on opposite sides in the 2007 election.
Mr Kenyatta backed President Mwai Kibaki, while Mr Ruto was part of Raila Odinga's alliance seeking to oust the president.
Munyori Buku, the director of communications in the deputy prime minister's office, said negotiations were ongoing "and when a deal is reached, it will be the prerogative of the party principals to announce it".
He apologised for his earlier statement and said the pair would be holding a joint rally in the Rift Valley town of Nakuru on Sunday.
The initial statement said the goals of their alliance would be "national unity, prosperity for all Kenyans [and] reconciliation".
It did not specify who would be their presidential candidate in March 2013 - a month before they are due to face trial in The Hague.
Both men have previously said they would contest the presidential election despite the ICC charges.
Civil society groups have gone to court, seeking to have the pair banned from the election because of the ICC charges.
Under the new 2010 constitution, holders of public office who are charged with a crime must step down.
Mr Odinga, who became prime minister under the deal brokered to end the bloodshed, is also expected to contest the presidential election.
Mr Kibaki is stepping down next year at the end of his second and final term.