For the past seven years, President Emmanuel Macron has basked in the largely undivided attention of the French nation, enjoying freedom in shaping the country's foreign and domestic policy.

The appointment of Michel Barnier, a 73-year-old traditional conservative, as Macron's new prime minister on Thursday marks the beginning of a new era for a president who once famously said he wanted to rule like Jupiter, the Roman god of the sky and thunder. 

Under the new power-sharing arrangement that the Elysee presidential palace calls an era of "demanding coexistence", Macron will cut a diminished figure both at home and abroad.

"We won't have the same presidency," said Anne-Charlene Bezzina, an expert in public law.

"It's up to the prime minister to get his hands dirty, to build alliances and coalitions. He's the one who'll be caught in the National Assembly's crossfire."

The appointment of Barnier marked a potential turning point following two months of political chaos in the wake of snap elections called by Macron that left no group close to an overall majority in the National Assembly lower house of parliament.

Barnier, a former foreign minister who acted as the European Union's Brexit negotiator, quickly indicated he would be his own man.

"The president will preside and the government will govern," Barnier, the oldest premier in the history of modern France, said on Friday evening.

Macron is expected to be the "guarantor" of France's institutions and no longer dictate government policy.

Having been known for his top-down leadership style since coming to power in 2017, observers say Macron will have to learn humility.

'Can't stand still'

The Elysee presidential office and Matignon, the office of the French prime minister, will no longer share advisers, as has been the case for the past seven years, and Macron's advisers will no longer attend interministerial meetings.

Barnier will be in charge of the budget, security, immigration and healthcare, and will have to take into account the interests of the far-right National Rally, the single largest party in a fragmented parliament, to avoid a motion of no confidence.

Barnier, a member of the right-wing Republicans (LR) party who is not affiliated with the president's centrist faction, has promised "change".

"We're going to do more than just talk," he said. 

But some are sceptical that Macron will be able to take a back seat on the home front.

"Emmanuel Macron can't stand still. He won't be able to remain on the sidelines," said a former presidential adviser, asking not to be named. "At the slightest jolt, he'll be back."

Political scientist Vincent Martigny said he would be surprised if Macron "stopped intervening".

"Politicians don't change, least of all Macron," said Martigny. "They have a method, a personality."

Macron's parliamentary group, Ensemble pour la Republique, which has 99 seats, has ruled out any "unconditional" support for Barnier but is expected to be the government's main bulwark in the lower house.

Several outgoing ministers could also be reappointed, with powerful Interior Minister Gerald Darmanin letting it be known he is keen to stay on, possibly with a promotion to the foreign ministry. 

Bezzina said that Barnier comes from the centre right, and "it would be incredible" if he became "a violent opponent of someone whose matrix is relatively compatible".