JERUSALEM, Jan 1 (Reuters) - Israel's Supreme Court on Monday struck down a highly disputed law passed by Prime Minister Benjamin Netanyahu's right-wing government that rolled back some of the high court's power and sparked months of nationwide protests.
The law was part of a broader judicial overhaul proposed by Netanyahu and his coalition of religious and nationalist partners which caused a deep rift in Israel and concern over the country's democratic principles among Western allies.
Monday's court decision could test the cohesion of an emergency government formed to manage the war against Hamas, which includes hardline proponents like Finance Minister Bezalel Smotrich and critics of the judicial overhaul such as centrist Benny Gantz and Defence Minister Yoav Gallant.
Smotrich dismissed the decision as "extreme and divisive", echoing the bitter divisions that marked Israeli politics in the months before the deadly Hamas rampage through southern Israel on Oct. 7.
The new legislation brought before the court had removed one, but not all, of the tools the Supreme Court has for quashing government and ministers' decisions. It took away the court's ability to void such decisions that it deemed "unreasonable".
Twelve of 15 justices ruled that it was within the court's parameters to strike down quasi-constitutional "basic laws". A smaller majority of eight ruled to nullify this specific basic law, which the court said "causes severe and unprecedented harm to the core characteristics of Israel as a democratic state."
Some Israeli officials have acknowledged that the internal divisions caused by the judicial overhaul - which seeped into the military and prompted Netanyahu to temporarily fire Gallant, who had called to halt the reforms - may have factored into Hamas' decision to carry out its Oct. 7 killing spree.
Netanyahu's Likud party said the Supreme Court's decision was unfortunate and that it opposed "the will of the people for unity, especially during wartime". It did not discuss any possible steps it might take in its brief statement.
Yair Lapid, opposition chair and a former prime minister, praised the court, whose decision he said "seals a tough year of dispute that tore us apart from the inside and led to the most terrible disaster in our history."
The Supreme Court, according to its summary of the case, said the government in passing the amendment to the basic law "completely revoked the possibility of carrying out judicial review of the reasonableness of decisions made by the government, the prime minister, and the ministers."
"The court held that the amendment causes severe and unprecedented harm to the core characteristics of Israel as a democratic state."