Netanyahu's Likud Party criticized the decision, describing it as “contrary to the nation's desire for unity, especially in times of war.”
“Today, the Supreme Court faithfully fulfilled its role in protecting the citizens of Israel,” Israeli opposition leader Yair Lapid said on Twitter previously.
Monday's ruling concerns an amendment to Israel's “Basic Law,” which replaces the constitution, and was passed and approved by Netanyahu's far-right government in July. The amended law removes the right of the Israeli Supreme Court to block decisions made by government ministers that judges consider “unreasonable.”
In repealing the law 8 to 7 on Monday, the Supreme Court ruling calls for the legislation to be removed. If Netanyahu's government refuses to respect the ruling, the wartime state could face a constitutional crisis.
The reform plan, first proposed by Netanyahu's coalition last January, sparked widespread social unrest that lasted nearly a year and sparked extraordinary opposition from the military and senior security officials.
Supporters of the legislation said it was a necessary correction to an activist Supreme Court led by a coterie of elite judges. Opponents said the law could lead to tyranny and pave the way for Netanyahu's far-right and ultra-Orthodox supporters to change the main foundations of Israel's liberal democracy.
Weekly protests against the proposal attracted hundreds of thousands of people. Military pilots and soldiers threatened not to report for voluntary service if the government refused to back down from its plan.
In March, Netanyahu fired his defense minister, Yoav Gallant, after Gallant called on the government to halt its plan, warning of potential security problems for Israel if reservists withdraw. Gallant was reinstated two weeks later.
President Biden, one of Israel's staunchest allies, in March also opposed the law in a rare public disagreement. “I hope he moves away from that,” Biden said, adding that Netanyahu’s government “cannot continue down this path.”
Melin reported from Tel Aviv.