Hundreds of protesters broke into Mexico’s Senate as lawmakers weighed a radical reform to overhaul the country’s judiciary, forcing the upper house to take a temporary recess for the safety of the senators.

The shutdown came just hours after Mexico’s ruling party, Morena, wrangled the votes it needed to push through the proposal after one member of an opposition party flipped to support it.

That move and other political manoeuvering ahead of a vote on the plan championed by outgoing President Andres Manuel Lopez Obrador fuelled even more outrage after weeks of protests by judicial employees and law students.

The Senate gave general approval to the plan that critics fear could threaten the rule of law and damage the economy early on Wednesday with 86 to 41 votes in favour.

The body will now move to debating reservations raised by lawmakers before giving final approval to the reform which passed the lower house last week.

Critics and observers say the plan, in which all judges would be elected, could threaten judicial independence and undermine the system of checks and balances.

Some protesters entered the Senate chambers in an effort to block the vote after they said lawmakers were not listening to their demands. Others broke through the door of the Senate, using pipes and chains.

“The judiciary isn’t going to fall,” shouted the protesters, waving Mexican flags and signs against the overhaul. They were joined by a number of opposition senators as they chanted in the chamber. Others outside the court roared when TV broadcasters announced the Senate was taking a recess.

Lopez Obrador claims his plan would crack down on corruption by making it easier to punish judges. Critics say it would handicap the judiciary, stack courts with judges favouring the president’s party, allow anyone with a law degree to become a judge and even make it easier for politicians and criminals to influence courts.