PARIS — French President Emmanuel Macron imposed a highly unpopular bill raising the retirement age from 62 to 64 on Thursday by shunning parliament and invoking a special constitutional power.

Lawmakers were shouting, their voices shaking with emotion as Macron made the risky move, which is expected to trigger quick motions of no-confidence in his government. Riot police vans zoomed by outside the National Assembly, their sirens wailing.

The proposed pension changes have prompted major strikes and protests across the country since January. Macron, who made it the flagship of his second term, argued the reform is needed to keep the pension system from diving into deficit as France’s population ages and life expectancy lengthens.

The decision to invoke the special power was made during a Cabinet meeting at the Elysee presidential palace, just a few minutes before the scheduled vote, because Macron had no guarantee of a majority in France’s lower house of parliament.

Then, as Prime Minister Elisabeth Borne tried to formally announce the decision at the National Assembly, leftist members broke into the Marseillaise, the French national anthem, delaying her speech. The speaker had to briefly suspend the session to restore order.

“Today, there’s uncertainty” about whether a majority would have voted for the bill “by just a few votes,” Borne explained. “We cannot take the risk to see 175 hours of parliamentary debate collapse … We cannot gamble on the future of our pensions. That reform is necessary,” she said.

Borne said her government is accountable to the parliament, prompting boos from the ranks of the opposition.

“In a few days, I have no doubts … there will be one or several no-confidence motions. There will actually be a proper vote and therefore the parliamentary democracy will have the last say,” she added.

Lawmakers on the left and far right quickly confirmed their next moves.

Marine Le Pen said her National Rally party would file a no-confidence motion, and Communist lawmaker Fabien Roussel said a motion is “ready” on the left.

“The mobilization will continue,” Roussel said. “This reform must be suspended.”

To be adopted, a no-confidence motion needs to be approved by at least half the seats at the lower house — that is 287 now. In such case, which would be a first since 1962, the government would have to resign.

If no-confidence motions don’t succeed, the pension bill would be considered adopted.

Earlier Thursday, the Senate adopted the bill in a 193-114 vote, a tally that was largely expected since the conservative majority of the upper house of parliament favors raising the retirement age.

Macron’s alliance lost its parliamentary majority last year, forcing the government to count on conservative lawmakers to pass the bill. Leftists and far-right lawmakers are strongly opposed and conservatives are divided, which made the outcome unpredictable.

The French leader wants to raise the retirement age so workers put more money into the system, which the government says is on course to run a deficit.

Macron has promoted the pension changes as central to his vision for making the French economy more competitive. The reform would raise the minimum pension age and require 43 years of work to earn a full pension, amid other measures.

Nearly 500,000 people protested against the bill around the country Wednesday.

Economic challenges have prompted widespread unrest across Western Europe. In Britain on Wednesday, teachers, junior doctors and public transport staff were striking for higher wages to match rising prices. And Spain’s leftist government joined with labor unions to announce a “historic” deal to save its pension system by raising social security costs for higher wage earners.