Colombian judges Tuesday approved special fast-track procedures to implement the government's contested peace accord with leftist FARC rebels which aims to end half a century of conflict.

The government says the fast-track reforms are needed to see through the peace deal before a fragile ceasefire collapses.

Constitutional court judges voted eight to one in favor of the measure, the court said.

The decision gives the green light to President Juan Manuel Santos to use accelerated legislative procedures to pass the various reforms included in the peace accord through Congress, where his side holds a majority.

Under the deal, the Revolutionary Armed Forces of Colombia, or FARC, must demobilize and surrender their weapons within six months.

The FARC will relaunch as a political party and its members will receive an amnesty or non-custodial sentences -- the most contested part of the accord.

Santos's opponents argue the deal grants impunity to rebels guilty of war crimes.

Voters rejected an earlier version of the deal in a referendum in October, forcing the government and FARC to revise the accord.

Opponents say the new version includes only token changes.

Colombia's civil conflict has drawn in various armed groups over the decades. It has killed more than 260,000 people.