JERUSALEM (Reuters) - An Israeli soldier who was sentenced to 18 months’ imprisonment for killing a wounded and incapacitated Palestinian assailant appealed on Wednesday against a manslaughter conviction that could have sent him to jail for a maximum 20-year term.

Israeli soldier Elor Azaria (R), convicted of manslaughter, arrives to a military court where arguments for his sentencing will be heard in Tel Aviv January 24, 2017. REUTERS/Debbie Hill/Pool

Three of Elor Azaria’s defense attorneys said after the appeal was announced that they were quitting. In a statement, they said he had received a “fantastic and seemingly impossible” sentence, appearing to suggest he should not put it at risk.

Azaria’s trial - sentence was passed on Feb. 21 - was one of the most divisive in Israel’s history. In one opinion poll, nearly half of Israeli Jews said any Palestinian attacker should be killed on the spot.

Eleven months ago, Azaria was serving as an army medic in the town of Hebron in the occupied West Bank when two Palestinians stabbed and wounded another soldier.

One of the assailants was shot dead by troops. The other was shot and wounded. Eleven minutes later, as the wounded man, Abd Elfatah Ashareef, 21, lay on the ground unable to move, Azaria, then 19, took aim with his rifle and fatally shot him.

A three-judge military court convicted Azaria of manslaughter last month. It rejected his contention that he believed the man still posed a threat, admitting into evidence a video of the incident recorded by a Palestinian rights activist.

Imposing punishment lighter than a three-to-five year sentence requested by the prosecution, the court noted the Hebron incident had been Azaria’s first combat experience and that his record had been unblemished.

The Palestinian government said the term imposed by the court had given Israeli soldiers a “green light” to carry out “executions without fear of real punishment”.

In the statement announcing their resignation, the three defense lawyers also said that while they believed Azaria never should have been convicted, they had proposed to the soldier and his family that he pursue other options.

Those include a presidential pardon - which cannot be considered while an appeal process is ongoing - or a procedure in which an a military general can opt to reduce his sentence.

In the petition to a military appeals court, Azaria’s remaining lawyer asked that the start of his incarceration, on March 5, be deferred until the end of legal proceedings.

Prosecutors, who have yet to decide whether to lodge an appeal for a stiffer sentence, had originally considered charging Azaria with murder. But they said it would have been difficult to meet the legal requirement of showing premeditation.