As a former conservative, he has “good relations with Les Républicains party” and represents “continuity” with the president’s past governments, Emmanuel Macron said. | Nicolas Economou/Getty Images

This week, Socialist Party leader Olivier Faure warned that no Socialist would join Lecornu’s government and “if nothing changes” they would not shy from toppling the government.

If the moderate left remains outside the government, they will want to extract a high price for their tacit support. And on budget talks, there’s a massive gap to bridge.

The Socialists want to suspend Macron’s flagship reform of pensions, a red line for the president. They also want a tax on France’s ultra-rich individuals, the so-called Zucman tax, which has been slammed by Macron’s centrists as a futile proposal that will just encourage France’s wealthiest to move abroad.

Macron, however, has signaled some room for maneuver on the scale of the budget cuts needed. Bayrou’s plans to squeeze the 2026 French budget by €43.8 billion may well be shelved. The president “prefers structural reform to lopping €3 billion off the budget,” said the ally quoted above.

There might be a way. “If he refuses the Zucman tax but increases the minimum wage, we’ll take a look,” said a Socialist official.

Ultimately, Lecornu’s secret weapon could turn against him. The man who has Macron’s full confidence may have to extract uncomfortable concessions from his own boss — if he wants to survive as prime minister.

This story has been updated.