Colombia's government and Marxist guerrillas scrambled 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 referendum result that plunged the nation into uncertainty, Reuters reported. Any renegotiated peace accord now seems to depend on whether the Revolutionary Armed Forces of Colombia (FARC) could accept some tougher sanctions against them. "No" voters, who narrowly won Sunday's plebiscite, want assurances the rebels will hand in cash from drugs, spend time in jail, and earn their political future at the ballot box rather than get guaranteed unelected seats in Congress. Both President Juan Manuel Santos and Rodrigo Londono, the top FARC commander better known by his nom de guerre Timochenko, put a brave face on the referendum setback after their teams had negotiated for four years in Havana. They vowed to maintain a ceasefire and keep working together, even though that could now be another lengthy and complicated process. "I will keep seeking peace until the last minute of my term," said Santos, who leaves office in mid-2018. In a statement, the FARC said it would "remain faithful" to the accord signed last week with the government and called on Colombians to mobilize peacefully to support terms of the existing agreement. Latin America's longest conflict has killed 220,000 people, displaced millions and brought atrocities on all sides. Santos, whose political image has taken a beating with the result, planned to meet all political parties on Monday. Chief government negotiator Humberto de la Calle offered to resign, but the president is unlikely to accept that and in fact asked him to return to Havana to re-open new talks. International exhortations for Colombia to stay on the path to peace came flooding in.