Defence Minister Agustín Rossi on Thursday accused a group of retired Army officers of conspiring to destabilise President Alberto Fernández's government.
Rossi, slammed the group after a picture of the officers meeting in Buenos Aires appeared in the media, which also quoted some of the group's manifesto.
The minister slammed the gathering as "an absolutely unprecedented act in the democratic life of the country," adding that it was an affront to the current military leadership and their commander-in-chief Fernández.
Memories are still fresh in Argentina of the iron-fisted 1976-83 military dictatorship which left an estimated 30,000 people missing or dead, according to human rights organisations.
"They present themselves as an alternative to the official military leadership which is the heads of the Armed Forces, appointed by the commander-in-chief, who is the president of the nation," Rossi told the AM750 radio station.
"Clearly, this is an action that seeks to conspire, destabilise and try to question the role of the defence policy being pursued by the government," the minister said.
Human rights leaders also expressed concern. Estela de Carlotto, the president of Grandmothers of the Plaza de Mayo, said she was "concerned" by the meeting.
"These people are not sleeping and are continuing to dream of dictatorial power," she said.
The group, a so-called 'liason board', said it plans to participate in the public debate over Argentina's defence and national security.
Media reports said key members of the group are retired generals Ernesto Bossi and Daniel Reimundes, both former heads of the military's Life Insurance Society SMSV.
"Bossi is a born conspirator," said Rossi, saying he was a former member of the SIDE state intelligence service.
Bossi rejected the accusations in an interview in the daily Clarín, saying the group had no intention of undermining Argentina's constitution.
"From the beginning we know that an idea like ours always generates mistrust. But there is a change in attitude, we are not wasting energy defending ourselves from accusations that have no foundation. We are not part of any conspiracy, nor, of course, do we encourage it. For us, respect for the constitution and the whole legal framework is not in discussion."
The heads of the Malvinas War Veterans' Association and an Army welfare group said in a statement they were invited to participate in Wednesday's meeting but declined to join the initiative.