Kuwait's constitutional court ruled on Tuesday that the Gulf emirate's electoral constituency law was in line with the constitution, rejecting a government appeal.
"The recourse is rejected," judge Faisal al-Murshid, Kuwait's chief justice, declared in a short verdict, a day after thousands of opposition supporters rallied against the government's attempt to redefine the constituencies.
Last month, the government asked the constitutional court, whose verdicts are final, to rule if the electoral constituency law was not in breach of the 1962 constitution.
The verdict was issued in a packed courtroom amid unprecedented security measures with dozens of riot police backed by armoured vehicles deployed around the Palace of Justice where the one-minute session was held.
Dozens of opposition activists who were in the court room hailed the verdict and exchanged congratulations.
The verdict is expected to ease hightened tension in the oil-rich Gulf state where the Islamist and national opposition has been locked in ongoing disputes with the government controlled by the Al-Sabah ruling family.
Prominent opposition figure and MP Mussallam al-Barrak praised the verdict and demanded the 2009 pro-government parliament be dissolved immediately and fresh election held.
The 2009 "parliament must be dissolved immediately and fresh election should be held on the basis of the same constituency law," Barrak told AFP as he walked out of the courtroom.
"The government must be punished politically ... because it cannot be trusted to run the affairs of the country," the outspoken lawmaker said.
The law, which divides the oil-rich Gulf state into five electoral districts, was passed by parliament in 2006 following popular rallies demanding reform of the electoral process.
Parliamentary elections were held on the basis of the law in 2008 and 2009, in addition to February 2012 which the constitutional court nullified in June on the grounds of procedural flaws.
The ruling was preceded Monday by a massive rally by opposition supporters as speakers warned that a "politicised" verdict making the law unconstitutional could take Kuwait into a dark tunnel.
Opposition leaders had claimed the move was an attempt by the government to unilaterally change the constitutional system in place for a half century.
In an unprecedented ruling in June, the same court scrapped the opposition-controlled parliament elected in February and reinstated the previous pro-government house elected in 2009 after it was dissolved in December following youth-led protests.
OPEC member Kuwait has been rocked by a series of political crises since 2006 during which the government resigned nine times and parliament was dissolved on five occasions.