The head of Israel's Supreme Court has accused government allies of waging a poisonous campaign against the judiciary, saying they were undermining the legal system's cherished independence.

Judge Dorit Beinisch's attack, described as "unprecedented" by the media on Friday, stunned Israel's political elite and fuelled a long-running fight over the make-up of the courts.

Speaking at a legal conference on Thursday, Beinisch said the judiciary faced: "a delegitimisation campaign headed by several politicians, parliamentarians and even government ministers, who propagate false and misleading information".

She added that this had "reached the point of incitement against the courts, its judges and its judicial undertakings."

Her comments were widely interpreted to be aimed at a group of politicians within Prime Minister Benjamin Netanyahu's conservative-religious coalition who have put forward a host of bills in recent weeks that critics denounce as anti-democratic.

Senior right-wing politicians immediately hit back.

"I will not break under a campaign of threats and intimidation and will continue to lead a practical discourse of legitimate reforms needed in the legal system," said Zeev Elkin, the chairman of the ruling coalition.

Beinisch took particular aim at a bill to let parliament vet and veto Supreme Court nominees -- a measure some say is needed to bring greater diversity into the top halls of justice.

The Supreme Court, viewed as the ultimate arbiter for protecting civil rights in Israel, is still dominated by secular Jews of European descent. Just one of the court's 13 judges is an orthodox Jew while the only one who originated from Jewish communities in the Middle East and north Africa has retired.

By contrast, parliament and the government host a large number of representatives from both these groupings. They say the court should better reflect their growing prominence.

Netanyahu effectively froze the bill last month in the face of widespread concern over any politicisation of the judiciary, but Beinisch said the reputation of the courts was jeopardised by constant political sniping.

"The deception campaign, by its very nature, permeates and poisons. This is the nature of propaganda," said the judge, who is due to retire early next year.

Her attack looks certain to heat up an already charged legislature, which has been marked by a string of heavily contested bills put forward by coalition partners.

Among the bills stirring up controversy is an attempt to limit foreign government donations to NGOs. European diplomats in Jerusalem say this is designed to neuter groups opposed to the continuing Israeli occupation of the West Bank.

Another bill has drawn the ire of media groups for hiking damages in libel cases and loosening the definition of slander.

"[Beinisch's] speech expresses, in the clearest way, the ill winds that are blowing in the Knesset," Yoel Hasson, a member of the Kadima opposition party, was quoted as saying on Friday.