Kenya's President Mwai Kibaki, who led a coalition of opposition parties to electoral victory three years ago by promising a new constitution within a 100 days, has a date with destiny on 21 November.
By Waihenya Kabiru
BBC News, Nairobi
The "Orange" and "Banana" camps have split coalition and country
An estimated 11 million people are registered to vote in a referendum to decide whether to accept a proposed new constitution.
The president is leading the "Yes" campaign under the symbol of a banana against seven of his cabinet ministers, who have broken ranks with the government to oppose the draft.
The rebel ministers championing the "No" vote - symbolised by an orange - are led by forceful Roads Minister Raila Odinga, the man credited with Mr Kibaki's 2002 election victory after he endorsed his candidacy for the opposition coalition.
The draft is a hybrid document made up proposals by a national constitutional conference, plus amendments made by a parliament controlled by Mr Kibaki's allies.
The major bone of contention between the "Banana" and "Orange" activists is the structure of government.
The "Orange" side say the proposed constitution vests too much power in the president, creating an imperial presidency.
The referendum will be the culmination of bitter rifts in President Kibaki's coalition
The rebel ministers favour a constitution where a powerful prime minister shares executive powers with the president.
The "Banana" side, however, say that is tantamount to handing over the powers of a popularly elected president to an unelected prime minister.
Monday's referendum will be the culmination of bitter rifts in Mr Kibaki's fragile Narc coalition.
He has been accused by his rebel ministers - from Mr Odinga's Liberal Democratic Party (LDP) - of reneging on a pre-election pact to share power equally once the coalition dislodged retired President Daniel arap Moi's Kanu party from power.
The LDP had fallen out with Mr Moi over his choice of successor, but now the political realignments have come full circle and they find themselves back in the camp of Mr Moi's Kanu party fighting the constitution.
And so the battle lines have been redrawn - indeed, the referendum has been seen as dress rehearsal for 2007 general elections.
Ordinary fruit have taken on deep political significance
A win for Mr Kibaki's "Yes" side would greatly enhance his reputation and give him the mandate to kick out rebel ministers from his government - something he has indicated he will do whatever the outcome.
Although rebel ministers say they will resign if their side loses the vote, their fate seems a foregone conclusion.
"We will definitely sack some people," the president said during a campaign tour of western Kenya.
Opponents of the draft, meanwhile, say the Kibaki government ought to resign if it loses the referendum vote, arguing Kenyans will have delivered a vote of no-confidence in the government.
The "Orange" campaigners have already said they will call for mass action to force the government out of office if it wins.
This has heightened political temperatures in the country, with the government warning it will deal firmly with any acts of violence and civil disobedience.
During campaigning, nine people have been killed in violence mainly at rallies organised by the "No" vote.
Four of the deaths occurred in the western city of Kisumu, where Mr Odinga commands an almost fanatical following.
Angry words have spilt over into violence at rallies
Afterwards, he said he was ashamed of serving in the Kibaki government, which he accuses of being responsible for the killings.
After the referendum, the battle ground will move to parliament, where there is the possibility that rebel ministers and their opposition partners in Kanu will initiate a vote of no-confidence in the government, especially if the referendum goes their way.
Fears of such an eventuality have prompted Mr Kibaki to bring members of other opposition parties into government.
The "Orange" side says if the constitution is rejected, they will re-introduce the original draft constitution to parliament, which waters down presidential powers.
The worry for investors and the donor community is that the fallout from the referendum vote could spill into violence.
For Kenyans, no matter which fruit claims victory, they can look forward to their longest election campaign ever as politicians strategise for 2007.