Israeli police responded with force to protests across the country as lawmakers forced ahead with judicial changes that opponents see as a threat to democracy.

Police fired stun grenades in Tel Aviv and scuffles broke out across the country, according to reports.

"Israel is not a dictatorship, Israel is not Hungary," protesters blocking the main highway from Tel Aviv to Jerusalem shouted, waving blue and white Israeli flags.

Tel Aviv police on horseback tried to stop demonstrators from breaching barricades as traffic piled up. Live footage showed police dragging protesters off the road as demonstrators called out "shame" and "we are the majority and we are out on the streets". At least nine people were arrested, police said.

Demonstrations were expected to intensify in what protest organizers have dubbed a "day of disruption."

Israel's far-right National Security Minister Itamar Ben-Gvir said he would not allow "anarchists" to block roads.

Prime Minister Benjamin Netanyahu's nationalist-religious coalition government proposed what it has described as a reform of the judiciary in January.

It includes giving ruling coalition lawmakers a decisive sway in picking judges and limiting the Supreme Court's scope to strike down legislation or rule against the executive.

In parliament, the Knesset's Constitution, Justice and Law Committee gave initial approval to more proposals in the plan, in a vote boycotted by opposition lawmakers.

Critics say the proposals undermine judicial independence, given Israel has no constitution and only one house of parliament, controlled by Prime Minister Benjamin Netanyahu's far-right coalition.

The plan has yet to be written into law, but it has already affected the Israeli shekel and drawn concern from some Western allies about the health of democracy.

"Slow down a little a bit, maybe bring people together, try and build some consensus," U.S. Ambassador Tom Nides said at Tel Aviv University's conference of the Institute for National Security Studies on Tuesday.

Netanyahu, on trial on corruption charges that he denies, says the changes will restore the balance between the branches of government and boost business. Economists and legal experts have said they will isolate Israel and wreak havoc on the economy.

Polls have shown the plan is unpopular with most Israelis who would prefer a compromise be reached. Warning the country was on the brink of "constitutional and social collapse", President Isaac Herzog is pushing for an agreed accord.