The judicial revamp has split the nation and sparked one of the biggest protest movements in Israel's history, with weekly demonstrations often drawing tens of thousands.

Prime Minister Benjamin Netanyahu's hard-right government unveiled in January the plans to limit the judiciary's powers, which the protesters view as a threat to democracy.

On Friday at least 1,142 air force reservists declared their intention to suspend volunteer service if parliament passes the bill next week.

"We all share a responsibility to stop the deep division, polarisation and rift among the people," the reservists said in a declaration whose signatories included 235 fighter pilots, 173 drone operators, and 85 commando soldiers.

They called on the government to "arrive at a broad consensus, strengthen the trust of all parts of the people in the judicial system and maintain its independence."

Any legislation carried out in an "unreasonable manner would erode my agreement to keep risking my life and would force me, with great sorrow, to suspend my voluntary reserve service," the signatories said.

- 'Keep fighting' -

Most Israelis who complete their mandatory military service are expected to attend reserve duty every year for a specific period.

It is unclear how the country's military capabilities would be affected if reservists followed through on their threat, but it comes against a backdrop of worsening Israeli-Palestinian violence.

Defence Minister Yoav Gallant said he was "taking measures in order to reach a wide consensus".

Netanyahu, too, said late Thursday he was "still trying to reach an agreement with the opposition", mainly on the "reasonability" clause that allows the judiciary to strike down government decisions.

The bill is due for second and third readings in parliament on Monday.

If approved, it would be the first major component of the proposed legal overhaul to become law.

Other proposals include giving the government a greater say in the appointment of judges.

Thousands of protesters, including Guy Maidan, have been marching since Wednesday from the commercial hub of Tel Aviv to the seat of Parliament in Jerusalem, where they were to arrive for a demonstration later Saturday.

"We will keep fighting... unless this extreme government goes away," Maidan told AFP.

Young and old, he said, are keen on "saving Israel from going down towards not being a liberal democracy."

Netanyahu's government, which includes extreme-right and ultra-Orthodox Jewish allies, argues that the changes to the judicial system are necessary to ensure a better balance of power.

Critics accuse Netanyahu, who is on trial on corruption charges he denies, of trying to use the reforms to quash possible judgements against him.

He rejects the accusation.