French unions led another round of strikes and protests against President Emmanuel Macron’s pension reform, capitalizing on broad public support for a movement that has caused trash to pile up on the streets of Paris and sporadically turned violent.

The bill to raise France’s minimum retirement age to 64 from 62 has already passed parliament, but labor representatives are betting they can still force a U-turn. They are also seeking to maintain pressure ahead of a ruling by the Constitutional Council on the conformity of the overhaul due next Friday.

Unions continue to rally large turnouts at nationwide marches, tapping into rising anger after the government used a provision to dodge a National Assembly vote on the text. Still, early figures showed fewer public sector workers walked out on Thursday than on average since the strikes began in mid-January.

Scuffles broke out in cities including Paris. A march through the capital’s Left Bank was interrupted as some protesters attacked the storied La Rotonde brasserie, a former haunt of Hemingway and Fitzgerald where Macron celebrated his victory in the first round of the 2017 presidential election.

French rail operator SNCF warned of disruption on many lines, while the DGAC Civil Aviation Authority asked airlines to reduce flights by 20% at some regional airports including Marseille-Provence and Bordeaux. Garbage collectors have returned to work in Paris but plan to resume open-ended strikes next Thursday.

“We’re in a long-distance race,” Sophie Binet, the new leader of the leftist CGT union, said at the start of the march in Paris. “The government can’t run the country if it doesn’t withdraw this reform.”

The conflict over pensions is threatening to engulf Macron’s agenda of pro-business economic change that he has led since first taking office in 2017. Backing down at this late stage of the legislative process would be a hobbling political defeat, yet going ahead risks cementing his lack of a majority in parliament and destroying relations with unions that the government needs to work with on future overhauls.

The political debacle is also benefiting the far-right National Rally party. According to one survey by Ifop of 1,105 adults March 30-31, if there were a presidential election this weekend, perennial nationalist candidate Marine Le Pen would lead the first round of voting against any of Macron’s allies with as much as 36% of the vote. He cannot run for a third term in 2027.

A separate poll of 1,000 people by Elabe on Thursday showed Macron’s approval rating fell seven points in the last month to 25% - the lowest since the Yellow Vest protests that began in 2018.

The government and unions are now focused on the decision of the Constitutional Council, which will also rule on an opposition-backed request to put the bill to a referendum. However, unless it rejects the reform outright, the conflict over pensions will likely continue — at least until Macron enacts the changes later this year.

“A legal decision would add legitimacy to the law, but it wouldn’t erase political disagreements,” Labor Minister Olivier Dussopt said on BFM TV on Thursday.

Macron’s government says raising the pension age is vital to boost employment rates and halt the buildup of deficits in the massive public retirement system as the population ages. Unions say changing the age thresholds to claim a full pension will disproportionately penalize the least well-off and that there are other options to balance the system, including higher taxes on business and the wealthy.

Prime Minister Elisabeth Borne called a meeting with the leaders of France’s main unions on Wednesday in an attempt to discuss future changes to labor laws. They walked out after less than an hour as she refused their demands to drop the pension reform.

“We’re in a social crisis, we have a democratic crisis, there is a problem, and the president has the solution in his hands,” Laurent Berger, the leader of the reformist CFDT union, said on RTL radio ahead of Thursday’s protests.

Bloomberg’s Jenny Che and Maeva Cousin (Economist) contributed to this report.