JERUSALEM (Reuters) -Israel's military said on Friday it was examining the impact of a letter sent by air force reservists who threatened to stop volunteering for service if the government goes ahead with a planned judicial overhaul.

Spokesperson Daniel Hagari said the military was checking details of the letter that he said was initialled by more than 1,100 reservists and "accordingly, will examine the implications".

The letter, published in Israeli media without listing the signatories, was the latest sign of opposition within the military to judicial changes being pushed by Prime Minister Benjamin Netanyahu's religious-nationalist coalition.

It appeared to make at least some coalition members more intent on moving ahead with the changes.

"Even if we wanted to leave the legislation and stop, we simply cannot," said Finance Minister Bezalel Smotrich, one of Netanyahu's hard-right partners. "A country that gives in to threats of generals will actually be a country ruled by a military junta, which is the farthest thing from democracy."

Air force veterans say reservists who volunteer after completing their mandatory military service make up around half of crews sent on combat sorties.

Proponents of the judicial changes say they would restore balance to the branches of government. Critics say they would remove vital checks and balances. The drive has sparked months of unprecedented nationwide protests, bruised the economy and stirred concern among Western allies.

Defense Minister Yoav Gallant said in a statement that he was "working in all ways to bring about a broad consensus, prevent damage to Israel's security and keep the IDF out of the political dispute."

In a letter addressed to lawmakers, the military's chief of staff and the air force chief, the reservists called for broad agreements on the judicial overhaul and for the government to maintain the independence of the judiciary.

LOSS OF TRUST

"Legislation that allows the government to act in an extremely unreasonable manner will harm the security of the State of Israel, will cause a loss of trust and violate my consent to continue risking my life - and will lead, with deep sorrow and no choice, to a suspension of my volunteer reserve duty," the reservists wrote.

Reuters could not independently verify the reservists' identities or whether all of them still actively serve.

Hagari said the military was monitoring the situation, examining its readiness, and relaying the implications to the political leadership.

"Failing to report to reserve duty hurts the IDF and state security. Over the past days, it is evident that cohesion has been damaged, which will take a long time to repair," he said.

Before parliament breaks for summer recess on July 30, lawmakers are scheduled to vote next week on a bill that would block the Supreme Court from voiding decisions made by the government that it deems "unreasonable".

The seeping of the constitutional crisis into the military has jarred Israelis who have long seen the armed forces as an apolitical melting pot for a fractious society. On both sides of the schism, worries have been voiced about war-readiness.

On Monday, Netanyahu pledged to crack down on no-shows for military reserve duty, which he said risked inviting attack by Israel's foes and undermining its democracy.

"The government won't accept insubordination," Netanyahu told his cabinet.

(Reporting by Henriette Chacar and Ari Rabinovitch; Editing by Alison Williams, David Holmes)