PARIS — French Prime Minister Sébastien Lecornu unveiled key members of his new government on Sunday, ending weeks of uncertainty following his appointment last month.

Former Industry Minister Roland Lescure, an ally of President Emmanuel Macron who was in the running to become prime minister last year, will have arguably the toughest immediate challenge as he takes over from Eric Lombard as finance and economy minister. Tense talks over next year’s budget are already underway.

In a surprise twist, Bruno Le Maire, the former economy minister who left politics last year, returned to government take over as armed forces minister — the post Lecornu himself held until his recent promotion.

On the whole there are few fresh faces in Lecornu’s government, a sign that the political forces represented in Macron’s successive administrations remain broadly the same, despite Lecornu’s being the French president’s fifth prime minister in less than two years.

Many ministers from Macron’s centrist camp kept their posts, including Education Minister Elisabeth Borne and Overseas Territory Minister Manuel Valls — both former prime ministers themselves. Foreign Minister Jean-Noël Barrot, Justice Minister Gérald Darmanin and Budget Minister Amélie de Montchalin all stayed in post as well.

Bruno Retailleau, the hardline leader of the conservative Les Républicains, will remain as interior minister. Fellow conservatives Annie Genevard and Rachida Dati will stay on as agriculture and culture ministers, respectfully.

The 39-year-old Lecornu, a close Macron ally, has been handed the arduous task of trying to negotiate a slimmed-down budget after his predecessor, François Bayrou, was toppled in a no-confidence vote last month.

On Friday, Lecornu offered a significant concession to opposition parties by promising not to use a controversial constitutional maneuver that allows the government to pass legislation without a vote.

The former armed forces minister has signaled he is ready to make some major budgetary concessions to the left-wing socialist party to secure their support. But he must tread carefully to keep the conservative Les Républicains on board.

Retailleau had warned in recent days that his participation in the government was not set in stone and demanded assurances on the new Cabinet’s economic and immigration policy.