Israel's Supreme Court on Tuesday opened the first case to examine the legality of Prime Minister Benjamin Netanyahu's contentious judicial overhaul.

Netanyahu's government approved an amendment to a law in July to limit the powers of the Supreme Court.

All 64 lawmakers from the ruling right-wing coalition voted in favor of the text, with opposition members of the Knesset, Israel's parliament, boycotting the vote.

The amendment removes the court's ability to deliberate over and rule against government decisions it deems to be "unreasonable."

It is the first in a series of reforms by Netanyahu to reshape the judicial system. But the plans have sharply divided the nation. As the hearing got underway, dozens of protesters gathered outside the court on Tuesday.

Why is the hearing important?

Israel does not have a written constitution or a second chamber of parliament, meaning the Supreme Court is the only institution that keeps a check on the government's powers.

Instead, the country relies on 13 Basic Laws, special legislation that serves as a sort of constitution.

The amendment to the Basic Law on judiciary limits the court's power, with proponents saying the unelected judiciary wields too much control and that its power ought to be curbed.

The hearing on Tuesday puts the country's senior justices in an unprecedented position to decide whether to accept limits to their powers. The court has never struck down a Basic Law before.

In a sign of the case's significance, all 15 Supreme Court justices are hearing appeals to the law together for the first time in Israel's history.

A regular panel comprises three justices, though they sometimes sit on extended panels. The proceedings were also being livestreamed. 

Critics say the planned reform undermines Israel's democratic values and paves the way to authoritarian rule. They say Netanyahu also has a conflict of interest because he is facing trial on fraud charges, breach of trust and accepting bribes, all of which he has denied.

Israel has seen mass demonstrations since the government announced in January its plans to overhaul the judiciary.

Following widespread protests, the government has rolled back some of the more contentious reforms, including one that would have given the government more say in appointing judges.

rm/nm (Reuters, AP)