A former Israeli soldier who was sentenced to a 4.5-year prison term for leaking classified military papers, appealed her sentence before the Supreme Court Monday.

Anat Kam, who had served as a soldier at the Israeli army's Central Command in Jerusalem, was convicted in 2011 of leaking 1, 800 classified military documents to Ha'aretz journalist Uri Blau.

Kam's appeal follows Blau's plea bargain with the Prosecutors Office, according to which he will serve a four month community service sentence, after pleading guilty to possession of secret documents.

"There's a huge gap between both punishments," said Kam's lawyer, Ilan Bombach.

"They were nearly convicted on the same charges but Kam fully cooperated with the Shin Bet (Israel Security Agency) and other authorities, unlike Blau who fled the country," he added.

Bombach also said that Kam is planning to sue Blau over exposing her as his journalistic source. Kam became a journalist at the "Walla" website after her military service.

On the other hand, the prosecution said the punishment fits Kam 's actions.

"This is a uniquely severe affair," said prosecuting attorney Rachel Mater.

"Kam put in danger the lives of soldiers and civilians, and her hasty actions could have created an existential risk to the state of Israel," she said.

Presiding Judge Edna Arbel said it is "hard to belittle" the importance of the documents Kam passed to Blau.

The court will decide on Kam's appeal in September, after finalizing Blau's plea bargain.