Colombia goes to the polls in historic election that could see turn to left

Presidential frontrunner is former leftist guerrilla Gustavo Petro in country ruled for decades by the right

Colombians head to the polls today in a presidential election that may give the conservative South American country its first ever leftwing leader and first black vice-president.

Frontrunner Gustavo Petro, a former M-19 guerrilla fighter and senator, faces several rivals, but his main challenger is Federico Gutierrez, the former mayor of Medellin - Colombia's second city - who leads a rightwing coalition with close ties to the incumbent government of President Ivan Duque.