Colombia's government and Marxist FARC guerrillas will scramble on Monday to revive a plan to end their 52-year war after voters rejected the hard-negotiated deal as too lenient on the rebels in a shock result that plunged the nation into uncertainty.

 

Putting on a brave face after a major political defeat, President Juan Manuel Santos offered hope to those who backed his four-year peace negotiation with the Revolutionary Armed Forces of Colombia (FARC) in Cuba.

 

Latin America's longest conflict has killed 220,000 people.

 

"I will not give up, I will keep seeking peace until the last minute of my term," he said moments after losing Sunday's plebiscite to those who want a re-negotiation of the deal or an obliteration of the FARC on the battlefield.

 

Santos plans to meet all political parties on Monday and send lead government peace negotiator Humberto de la Calle back to Havana to speak to the FARC leadership.

 

Rodrigo Londono, the top FARC commander better known by his nom de guerre Timochenko, also offered reassurance the rebels remain committed to becoming a peaceful political party.

 

"The FARC reiterates its disposition to use only words as a weapon to build toward the future," Timochenko said after the result. "Count on us, peace will triumph."

 

Santos, 65, who was not obliged by law to hold a plebiscite, had said there was no Plan B for the failure of the peace vote, but now appears ready to consider options.

 

Colombians, even those who backed the "No" vote, expressed shock at the outcome and uncertainty about the future.

 

"We never thought this could happen," said sociologist and "No" voter Mabel Castano, 37. "Now I just hope the government, the opposition and the FARC come up with something intelligent that includes us all."

 

The peace accord reached last month and signed a week ago offered the possibility that rebel fighters would hand in their weapons to the United Nations, confess their crimes and form a political party rooted in their Marxist ideology.

 

SIXTIES ROOTS

 

The FARC, which began as a peasant revolt in 1964, would have been able to compete in the 2018 presidential and legislative elections and have 10 unelected congressional seats guaranteed through 2026.

 

That enraged "No" supporters, including powerful former president Alvaro Uribe, who argued the rebels should serve jail terms and never be permitted to enter politics.

 

Uribe, a onetime ally who has become Santos' fiercest critic, may now hold the key to any potential re-negotiation.

 

While the FARC has refused to serve traditional jail terms, it may see no future in returning to the battlefields and so consider some sort of new deal.

 

"In the end, the people have spoken: the Colombian government and the FARC have no choice but to renegotiate," said Peter Schechter, director of the Adrienne Arsht Latin America Center.

 

The FARC already softened its stance in the original negotiation, publicly admitting for the first time it trafficked drugs, recruited minors and committed human rights violations, including massacres.

 

But voters worried the rebels would fail to turn over assets from drugs and illegal mining, potentially giving them a formidable war chest that could outstrip the coffers of traditional parties.

 

Regions still riven by the conflict, including poor areas along the Pacific and Caribbean coasts, voted resoundingly in favor of the deal, but formerly violent interior areas pacified during the Uribe presidency largely backed the "no" camp.

 

"How sad. It seems Colombia has forgotten about the cruelty of war, our deaths, our injured, our mutilated, our victims and the suffering we've all lived through with this war," said Adriana Rivera, 43, a philosophy professor standing tearfully at the hotel of the "yes" campaign.

 

The vote may delay Santos' plans to move on to other matters including much-needed tax reform and other macroeconomic measures to offset a drop in oil income. It will also dent his hopes for a boom in foreign investment in mining, oil and agriculture in Latin America's fourth-largest economy.