THE annihilation of the Patriotic Union (UP), a small left-wing party created in 1985 as the political arm of the FARC guerrillas, was one of the darkest episodes in Colombia’s recent history. More than 3,000 members of the party, including two presidential candidates, were murdered during the 1980s and 90s by right-wing paramilitaries linked to the armed forces, as peace talks fell apart. The FARC have long cited the UP’s fate as a reason for their mistrust of democratic politics. Their opponents say that the FARC cynically used the peace talks and sacrificed the UP as a means of buying time to build up their guerrilla army—part of their strategy of “combining all forms of struggle”.

The antecedent of the UP hangs over the promising new peace talks that the FARC and Colombia’s government have been conducting in Havana since November. One item on the agenda is the need to provide the FARC with guarantees that they can enter politics once they have laid down their arms. So it was helpful to both sides that a court ruled on July 4th that the UP could have its legal status as a party restored. The loss of that status, because of the party’s failure to win sufficient votes in past elections, was because of extenuating circumstances, the court ruled.

Restoration was an “act of justice”, said Luciano Marín (also known by his nom de guerre, “Iván Márquez”), the FARC’s chief negotiator in Havana. He was elected to Congress for the UP in 1986, but was quickly recalled to the guerrillas’ ranks.

It is less clear whether the UP will prove to be a useful vehicle for the FARC or for the broader Colombian left. At its peak in 1986 it won only 4.5% in a presidential election. Today it is little more than a victims’ organisation. Another group, Patriotic March, now represents social movements that are close to the FARC.

Several other left-wing movements have risen and fallen since the 1980s. They have had some success, three times winning the mayoralty of Bogotá in different guises and gaining 22% of the vote in the 2006 presidential election. But the left has been dogged by division and, in some cases, by corruption and mismanagement in local government.

A new attempt is under way to form a united centre-left front ahead of next year’s presidential election. It would be better if this does not have the support of the FARC, according to Antonio Navarro Wolff, a possible candidate for the coalition. “Only when [the FARC] have signed a peace deal can we talk to them about politics,” he says. The killing by the FARC of 19 soldiers on July 20th, independence day, represented the army’s largest loss of life since the peace talks began. Two days later the FARC offered armed help to farmers in the north-east, who are protesting against the fumigation of their illegal coca plants and the lack of jobs.

The left’s weakness in Colombia owes much to the ambiguous position it has historically taken towards political violence and armed struggle. Today, much of that ambiguity has gone. But its legacy includes the risk that the FARC will face violence if they try to take any part in politics. And in turn it means that the left’s best chance of gaining support lies in the FARC giving up their guns once and for all.