Myanmar's highest court has upheld the dissolution of the party led by Nobel peace laureate Aung San Suu Kyi.
The court ruled that the National League for Democracy party would remain an unlawful association because it refused to register for the election last November.
The decision leaves Aung San Suu Kyi and the NLD outside formal politics in Myanmar.
The NLD won a resounding victory in Burma's last elections in 1990, but was kept from power by the military junta.
Lawyer Nyan Win told the BBC that there was nothing else the NLD could now do. But he said:
"Our existence and our legality does not change because of this court decision. Our party still exists. As Aung San Suu Kyi said, what really matters is the support of the people."
The BBC reports the bid to reinstate the party was previously dismissed four times by lower courts.
The new parliament opens in the capital Naypyidaw on 31 January.
Under a new constitution, the military is allocated 25% of seats in both houses of parliament and the state assemblies.