By Guido Nejamkis

BUENOS AIRES (Reuters) - Argentine President Cristina Fernandez told Congress on Friday she will not push for a constitutional overhaul that would let her run for a third consecutive term but will go ahead with a broad judicial reform proposal.

Fernandez, who has been in power for six years, will now have to step down after the next presidential election in 2015. Some of her supporters had sought a constitutional change allowing her to stand again.

"No constitution is going to be reformed, you can all relax," the left-leaning president told lawmakers in her annual state of the union address in which she outlined proposals aimed at "democratizing" the justice system.

They include holding public elections to pick members of the Magistrates Council, a powerful body that nominates and disciplines the nation's judges.

Fernandez also seeks new regulations to govern the use of injunctions, which she said had "distorted the law."

The president last year called for the judicial system to be "democratized" following controversial rulings such as the acquittal of all the defendants in a high-profile case of forced prostitution.

She also has criticized the courts for their handling of a dispute between the government and leading media conglomerate Grupo Clarin over a broadcast reform law that would force the group to sell off lucrative operating licenses.

Her anti-monopoly push has been frustrated by court injunctions favoring Clarin, which has become one of her leading foes due to the critical coverage of its news outlets.

Government supporters held balloons carrying the slogan "Clarin Lies" during Fernandez's 3-1/2-hour speech.

The legal reform proposal drew swift criticism from opposition lawmakers, some of whom said it was a thinly veiled attempt by the government to further tighten its control over state institutions

"We will fight to defend the justice system and I hope that this time the people will accompany us because without justice there is neither life nor liberty," said center-left lawmaker Elisa Carrio, who boycotted the president's address.

(Additional reporting by Alejandro Lifschitz and Helen Popper; Writing by Helen Popper; Editing by Xavier Briand)