By Dan Williams and Maayan Lubell
HEMED, Israel (Reuters) -Tens of thousands of Israelis opposed to a judicial overhaul sought by Prime Minister Benjamin Netanyahu marched to Jerusalem on Saturday, as pressure mounts on his right-wing government to scrap a bill that would curtail the Supreme Court's powers.
Carrying blue and white Israeli flags, a kilometres (miles) long column of protesters hiked up the winding highway to Jerusalem under a scorching summer sun, to the sounds of beating drums and anti-government chants and cheers.
The government's bid to change Israel's judiciary has plunged the country into one of its worst political crises, sparking nationwide protests, denting the economy and stirring concern among Western allies.
The protesters have been walking for days through a heatwave, camping out overnight and met by local residents offering food and drink, with their numbers swelling as they reached the city gates in an unprecedented sight.
They plan to rally outside parliament ahead of a Sunday debate and subsequent vote on the bill, which would limit the Supreme Court's powers to void what it considers "unreasonable" government or ministerial decisions.
Netanyahu's religious-nationalist coalition says the bill, which parliament is scheduled to vote on by Monday, is needed to balance out the branches of power because the Court has become too interventionist.
Critics say the amendment is being rushed through parliament and will open the door to corruption and abuses of power.
Polls suggest widespread misgivings among Israelis, and Washington has urged Netanyahu to seek consensus on any judicial reforms which should also keep Israel's judiciary independent.
The crisis has even sown divisions within the military, long viewed as an apolitical melting pot for a fractious society, with concerns about war-readiness voiced on both sides of the debate.
Dozens of former security chiefs, including military, police and Mossad heads, some of whom had served under Netanyahu, published an open letter to the premier on Saturday to call off the vote and negotiate widely agreed reforms instead.
"The legislation is crushing those things shared by Israeli society, is tearing the people apart, disintegrating the IDF (Israel Defence Forces) and inflicting fatal blows on Israel's security," the letter said.
Netanyahu, who is on trial for corruption that he denies, has said he has been striving for broad agreements and has placed the onus on opposition parties to make compromises.
(Writing by Maayan Lubell; editing by John Stonestreet and Clelia Oziel)