COLOMBIAN government and Farc liberation movement negotiators agreed on Thursday to sign a comprehensive peace deal to end decades of conflict by May 18.

Government representative Humberto de la Calle said citizens would vote on the final text in a referendum.

After the agreement is approved by Congress, the government will integrate the text into the state constitution and it will be effective the moment it is signed.

Thursday’s announcement provides legal assurance that a peace deal will be implemented and complied with by all parties.

The agreement includes a bilateral ceasefire and progress to Farc disarmament.

The two sides have successfully negotiated partial agreements on agrarian reform, political participation, illicit drugs and the rights of victims and transitional justice.

But both Farc and human rights groups have said that peace will not hold unless the government admits the existence of far-right death squads and acts to disarm them.