BOGOTA, Colombia -- "Uribe has a lot of unsettled scores," as do the "ranchers and businessmen who enriched themselves off land theft and drug trafficking," said Ivan Cepeda, a leftist congressman who wants Uribe in jail.

Uribe denies any association with such illegal groups.

But detractors say he successfully weakened the FARC in an alliance with shadowy groups that backed the far-right militias. More than 60 lawmakers allied with Uribe have been convicted of colluding with or benefiting from ties with far-right militias since 2006.

The case that prosecutors reopened against Uribe in January alleges that he and his brother Santiago formed a far-right militia on the family ranch, Guacharacas, in the Antioquia state town of San Roque in 1995, when Uribe was governor. Citing testimony from two imprisoned witnesses, prosecutors contend the ranch was used as a base of operations for the group, whose members allegedly committed "multiple crimes including massacres and selective killings."

Uribe did not respond to a question about the case during an interview with The Associated Press last month, but his lawyers have repeatedly denied the charges.

Uribe attorney Jaime Granados called the case "insane," and said he would prove "the whole thing is a farce."

While it is difficult to say whether Uribe's criticisms of the peace process have affected it in any way, the slow progress of the talks has only hurt Santos politically. He hasn't said he will run for re-election but has repeatedly stressed he will pull the plug on the talks unless significant progress is made.

Uribe is constitutionally barred from running again but has formed a political party that is expected to field a candidate. One potential nominee: the president's cousin, Francisco Santos, who was Uribe's vice president and now calls the current government "the most intolerant Colombia has had in many years."

That has led some to believe that President Santos wants Uribe out of commission, and that reopening the criminal case against him is just the way to do it.

Recent polls show Uribe with a higher approval rating than Santos: 65 percent compared to 44 percent, according to a mid-February survey conducted by Gallup. The same poll found 62 percent of Colombians said they didn't think a settlement will be reached in the peace talks. The poll surveyed 1,200 people and had a margin of error of plus or minus 3 percentage points.

Both sides have reported advances in the peace talks, particularly on agrarian reform, but have offered no specifics. Colombia is a country where 7 percent of the population owns 80 percent of the land, the National Office of Notaries and Registrars says, and more than 3 million people have been forcibly displaced by illegal armed groups, principally by far-right militias.

Changing the balance of ownership has been a chief demand of the rebels and just as fiercely opposed by wealthy ranchers.

The ranchers' chief spokesman, Jose Felix Lafaurie, has said the group opposes the peace process for the same reason as Uribe: No one should negotiate with "bandits."