The Argentine Congress has annulled amnesty laws that have for two decades protected members of the former military regime from prosecution on charges of human rights abuses.
By Peter Greste
BBC Argentina correspondent
In a late-night session, the lower house of Congress voted to scrap two key laws enacted soon after the regime fell.
The decision clears the way for hundreds of former military officers to be tried on charges of torture and murder.
A vocal minority of Argentines say the military was just doing its duty
In a packed chamber just before midnight, the Congress effectively opened the book on one of the most painful and brutal periods of the nation's history - the military dictatorship of 1976-1983.
Until now that book had been locked shut because of two laws which pardoned officers accused of human rights abuses and protected them from future prosecution.
But Argentina's President Nestor Kirchner came to office earlier this year promising to end impunity.
Public opinion seems to have swung solidly behind him. As Congress finally declared the laws annulled, a crowd of supporters gathered outside the building erupted in applause.
It was a historic step towards recovering the nation's humanity, declared one Deputy.
But this is only the beginning. Now the courts will have to sift through the thousands of allegations of torture and murder dating back to the period two decades ago commonly known as the Dirty War.
Human rights groups estimate that the regime kidnapped and executed as many as 30,000 people.
A vocal minority of Argentines still insist that the military was simply doing its duty, defending the country from left-wing insurgents. That view has now been swept aside, however.