"The House of Representatives voted in favour of suspending the law of political exclusion until the adoption of a permanent constitution," lawmaker Tarek al-Jerushi said, adding that the law could now be considered "annulled".
It is unclear how the authorities will be able to apply the law since the legitimacy of the parliament is disputed by a rival coalition that seized Tripoli last year.
The Islamist-led Fajr Libya group reinstated the General National Congress and formed a rival government when it overran the capital, forcing the elected parliament and government to take refuge in eastern Libya.
Its opponents have argued that it was adopted under pressure from armed groups which besieged government buildings in Tripoli for days until it was approved by the then transitional assembly.
The North African nation has been wracked by conflict since the overthrow and killing of Kadhafi in a 2011 uprising.
Powerful militias, backing rival governments and parliaments, have been battling for control of key cities and the country's oil riches.