Political parties in Kenya are holding their final rallies this weekend before voters choose a new president on Monday, amid controversy over comments attributed to one of the candidates.

The two top candidates held rallies before large and raucous crowds on Saturday, a day of political attacks and denials following a report that quotes one of them, the prime minister, as saying that election violence could be worse than it was in 2007-08 when more than 1,000 people died in ethnic clashes.

Monday's vote is the first nationwide election since Kenya's December 2007 vote devolved into tribe-on-tribe violence. Kenyan leaders and community groups have been working to ensure that massive violence isn't repeated, but fears linger that bloodshed will reappear.

The Financial Times in a story Saturday quoted Prime Minister Raila Odinga — one of the two top presidential candidates — as saying he knows his opponents are planning to rig the vote and "I have warned them the consequences may be worse than last time round. The people will not stomach another rigging."

Odinga denied making the statement and told a stadium full of supporters that the story was a "total fabrication." He said his campaign would petition the courts if it felt the results were problematic. An earlier statement said Odinga felt "absolutely slandered" and included a quote it said Odinga gave the paper:

"I am aware that my opponents are scaring my supporters so that they can migrate from where they registered in order to cut the spread of my vote. It is a form of rigging and Kenyans will not accept it. ... I will still win this election despite this dirty campaign."

Odinga's opponent calls comments 'dangerous'

The Financial Times did not release an audio recording of the interview.

Deputy Prime Minister Uhuru Kenyatta — Odinga's top challenger — called Odinga's words "dangerous and inflammatory" and he called on Odinga to retract them.

"We have in public, and our words and deeds throughout this election — all of us presidential candidates — committed to campaign in this election in peace, and just as importantly, to accept the result in peace," Kenyatta said. "So then why is it that at the most delicate time in the election campaign Raila sought to use such dangerous, inflammatory words?"

Rigging and cheating are a part of Kenyan elections, though international observers say they believe an improved electoral system will make wide-spread cheating harder this time. Many Odinga supporters believe that President Mwai Kibaki stole the vote from Odinga in 2007, a belief that propelled the violence.

Kenya's Deputy Prime Minister and then-finance minister Uhuru Kenyatta leaves the International Criminal Court in The Hague in this photo from April 8, 2011. He is to be prosecuted over violence following his country's previous disputed elections. (Bas Czerwinski/Associated Press)

Kenyatta and his running mate — William Ruto — both face charges at the International Criminal Court over allegations they orchestrated the 2007-08 violence. If Kenyatta wins, he may be forced to spend much of presidency before The Hague-based court.

Low-level fraud was evident Saturday, when a man approached an Associated Press reporter at Kenyatta's rally and asked if the reporter wanted to buy a voter registration card for about $12. The man gave his name as Calvin Juma Hongo and said: "Why should I waste my time voting for these guys? They don't care about me. All I am thinking about now is how to look after my pregnant wife."

The Kenyatta rally — with thousands of people clad in red — reached a peak frenzy as two helicopters circled the downtown park as Kenyatta was arriving. Kenyatta accused Odinga of taking success for granted, and he told his crowd he believes he can win in the first round. Ruto, in a reference to the newspaper interview, said no voter should be intimidated.

Julius Waweru, a 25-year-old studying to become an electrician, wore multiple Kenyatta hats. He said: "I support Uhuru Kenyatta because he is young, and we need to change this government for a younger generation."

Just down Nairobi's main street, perhaps 3 kilometres (2 miles) away, tens of thousands of supporters for Odinga filled a sports stadium. Supporters held a dozen or so American flags aloft. Odinga and President Barack Obama's father come from the same tribe.

Nicholas Owino, 56, a resident of Nairobi's Korogocho slum, wore a hat made of dozens of oranges, the colour of Odinga's party.

"My life is not good and I have not benefited from my support of Odinga since 2004 but I am confident if he becomes president my children will benefit," said Owino, who said he lost his grocery store during rioting of the 2007-08 violence and has not yet recovered it. More than 600,000 people were forced from their homes during the violence.

Odinga told the stadium crowd that Kenya has stagnated the last 50 years because the status quo has remained in power. "This can only change by voting in the forces of change," Odinga said.

He also appeared to attack Kenyatta, saying that the son of a snake is a snake. "It's time we end dictatorship, impunity and land grabbing," he said. Kenyatta is the son of Kenya's first president.

Monday's vote is the most important and complicated in the country's 50-year history. Despite efforts to promote peace, there are many reasons why the vote could turn tumultuous.

The Somalia militant group al-Shabab may try to attack voters or disrupt the vote; a secessionist group on Kenya's coast has threatened violence; new political divisions known as counties will see 47 new races for governor, creating sources of new friction; and tensions are high in some regions between Odinga's tribe — the Luo — and Kenyatta's tribe — the Kikuyu.

Odinga or Kenyatta must win at least 50 per cent of the vote in order to win the election Monday. There are eight presidential candidates, so it's likely the two will face each other in a run-off in April, a situation that analysts believe will raise tensions because of the increased focus on the two men.