PARIS — French unions and opposition parties are losing patience with new Prime Minister Sébastien Lecornu and his decision to keep quiet over his plans for next year’s budget.

Three weeks into his new job and with less than a week to go before a draft budget is due before lawmakers, Lecornu has yet to publicly offer much insight into his spending plans to the media, union leaders — whose members will go on strike Thursday — or party leaders.

Opposition lawmakers are once again raising the specter of torpedoing Lecornu, who has not yet named a Cabinet, over his continued silence.

“If nothing changes, the outcome is already known … This government will fall,” the Socialists’ leader Olivier Faure said.

Jean-Philippe Tanguy, who handles the far-right National Rally’s economic policy, accused the prime minister of trying to “buy time” by delaying budget announcements in an interview.

Union leaders, who have repeatedly accused Lecornu of ignoring their demands, will spend Thursday on the picket lines in the second general strike of Lecornu’s short tenure. His first full day as premier coincided with a nebulous movement to “block everything” that failed to materialize.

Lecornu has acknowledged his relatively tenuous position as a head of a minority government, and recent polling shows he enjoys the support of just a third of the French public. But the prime minister appears to be sticking to his guns in talks with the Socialists, the opposition party seen as most willing to negotiate.

A high-ranking Socialist lawmaker, granted anonymity to speak candidly, told POLITICO that the party “sincerely wanted to reach an agreement” with Lecornu to avoid a third government collapse in less than a year. The center-left party was instrumental in taking down Lecornu’s two immediate predecessors over their budget plans.

But, the lawmaker added, any deal would require Lecornu and President Emmanuel Macron to accept some “symbolic defeats.”

Faure and his party want the government to adopt the “Zucman tax,” a minimum tax to ensure that households worth more than €100 million pay at least 2 percent of their net worth in taxes each year, and reopen discussions on the unpopular 2023 pension reform that raised the minimum retirement age for most workers.

Faure said Tuesday that he expected a “full copy” of next year’s budget ahead of a meeting with the prime minister scheduled for Friday. He said his party would once again vote to take down the government if it does not see sufficient differences from the proposal put forward by former Prime Minister François Bayrou.

When he took office on Sept. 10, the 39-year-old prime minister pledged to break with the previous government “both on form and substance.”

Lecornu promised to abandon the unpopular idea to cut two public holidays, but in an interview with Le Parisien, he said he was not in favor of the Zucman tax because it would apply to professional assets. He did, however, acknowledge the widespread support for a more equitable tax regime. On retirement reform, which Macron has contended was necessary to keep the system solvent, Lecornu indicated changes were unlikely.

The prime minister told Le Parisien the 2026 budget will aim to bring the budget deficit down to around 4.7 percent of gross domestic product. The figure is projected to hit 5.4 percent of GDP this year.

Anthony Lattier contributed to this report.