Demonstrations were planned across the country as Netanyahu and his allies have pledged to press ahead with a series of bills that would strip the Supreme Court of its ability to review legislation and give coalition politicians control over judicial appointments.
Protesters planned to block highways leading to Israel's main international airport ahead of Netanyahu's departure to Rome for a state visit.
Police, overseen by ultranationalist National Security Minister Itamar Ben-Gvir, have pledged to prevent the disturbances. Israeli media reported the disruptions could force Netanyahu to change his travel plans to the airport.
The visit Thursday by U.S. Defense Secretary Lloyd Austin was also being affected by the protests.
An Israeli official said that Austin's meetings had been moved to a factory near the airport due to the expected disruptions.
The protest movement has been centered in central Tel Aviv, near the Defense Ministry.
The Israeli official spoke on condition of anonymity because they were not authorized to discuss the matter with the media.
On Thursday morning, military reservist protesters barricaded the Jerusalem offices of the Kohelet Forum, a conservative think tank that has helped craft the overhaul, with barbed wire and sandbags, and hung a banner outside reading "Kohelet is tearing Israel apart."
