PARIS — Emmanuel Macron has already won the first round of the fight to control parliament following his resounding presidential election victory.

Both the Socialists and the conservative Républicains can't hide their deep divisions over what to do after their own electoral defeats: Should they join the 39-year-old president-elect — or fight him?

The centrist former economy minister has already bested the two traditional major parties once — by starting his own political movement, En Marche ("On the move"), from scratch in April last year and going on to win the presidency while neither of their candidates reached the decisive second round of the election.

Macron now needs to win a majority in the lower house of parliament in elections due in June and wants politicians from both sides to join his camp. In response, the two parties' leaders have been trying to put up united fronts and paper over their respective internal divisions. But to no avail.

Macron now needs to win a majority in the lower house of parliament in elections due in June and wants politicians from both sides to join his camp.

Stung by their recent electoral disasters, influential politicians from both camps are indicating that they’re ready to rally around Macron without any further ado — and want to make that clear during the parliamentary election campaign.

Bruno Le Maire, a conservative former minister under presidents Jacques Chirac and Nicolas Sarkozy, has already indicated that he wants to be part of the “presidential majority.” Le Maire, who failed to win his party’s presidential nomination last year, said he was “ideologically close” to Macron and “ready to work in a presidential majority.”

That runs contrary to the official line of the Républicains, who have found a new temporary leader in François Baroin, the mayor of Troyes and briefly an economy minister under Sarkozy. Baroin has been tasked with leading the party’s parliamentary campaign and he is trying to keep it from falling apart. His aim is to secure an absolute majority of seats for the Républicains, force Macron to choose a conservative prime minister — a role Baroin would like for himself — and then try to set their own legislative agenda.

Baroin and his allies fear they would be walking into a trap by supporting a Macron presidency, leaving the role of opposition to the far-right National Front. Baroin has warned those tempted by collaboration with Macron that they would be excluded from the party and face one of its candidates in the upcoming election, which takes place over two rounds on June 11 and 18.

But a powerful group of former allies of Le Maire and ex-Prime Minister Alain Juppé, the favorite to clinch the Républicains presidential nomination before he lost out to François Fillon last November, think it is time for the party to decide whether it sees its future on the center-right or as a more conservative force.

Christophe Béchu, a Républicains senator and the mayor of Angers in western France, told POLITICO that his allies should seize the moment and join Macron in trying to reform France.

“We have a 39-year old president, both our big parties have failed, the French people want change and they want Macron to succeed,” he said. “Besides, this is France’s last chance. If he doesn’t keep his promise of renewal, it will be the National Front the next time. We must help him succeed.”

Béchu, a Juppé ally, last week wrote a column in Le Figaro to broach the idea of a German-style “grand coalition” between the two main parties. But he acknowledged that this could only now take the form of both camps helping Macron’s En Marche win a working majority in parliament.

Socialist schism

Things aren’t any clearer in the Socialist camp, where the same dilemma is tearing the party apart. Some government members such as junior foreign minister Jean-Marie Le Guen are eager to join Macron — following the example of Defense Minister Jean-Yves Le Drian, one of the new president’s early supporters. And former PM Manuel Valls has called for the party to be squarely in the “presidential majority.”

The party’s defeated presidential candidate Benoît Hamon, on the other hand, has called for a “united left” to field as many common candidates as possible in the parliamentary election. The alliance would be a broad coalition including Socialists, Greens and the communist party and perhaps even supporters of far-left presidential candidate Jean-Luc Mélenchon.

“We have a 39-year old president, both our big parties have failed, the French people want change and they want Macron to succeed" — Christophe Béchu, Républicains senator

Hamon sees the bloc as an opposition front against Macron, whom he fiercely criticized throughout the presidential campaign. His influence on the party is next to non-existent after his heavy defeat in the election, but he is not the only one to propose that line.

Macron has so far played his cards like an experienced gambler, in contrast to his image as a political novice. He initially said candidates who wanted to run with En Marche’s endorsement would have to leave their current political parties — but now he says that's not necessary, as long as they run as En Marche candidates and register as such if elected.

Now En Marche, soon to be rechristened "La République En Marche" and become a formal political party, has announced that the complete list of its candidates would be published by Thursday, giving potential Républicains and Socialist recruits a tight deadline for a difficult decision. Either they declare their support for Macron’s platform now — or they face the prospect of an En Marche candidate running against them.

What will make it harder for conservative bigwigs to decide is that Macron isn’t expected to announce his choice for prime minister until Sunday at the earliest — once he takes over as president. Some Républicains want to make sure that Macron is serious about his intention to govern with people of all stripes. They would be reassured by him choosing a PM from the center-right, as Macron himself hails from the Socialist camp.

“I’m expecting messages from the Macron people,” Le Maire said, adding that the new president should make sure the center-right would feel comfortable governing with him.

As if on cue, the first serious rumor out of the Macron camp on Monday suggested Edouard Philippe, the 46-year old Républicains MP and mayor of Le Havre in Normandy, would be the next prime minister. Philippe, a Juppé ally, checks all the boxes and fits the definition that Macron has given of his PM: a politician who would be able to get a legislative agenda through parliament. Philippe would also be a new face in government, having never held any cabinet job before. And there is no doubt that he would make many center-right politicians “comfortable” in a Macron majority.

Philippe becoming Macron’s PM would most probably lead to a split of the Républicains party, as Béchu acknowledged. And on the left, the Socialists’ existential angst would also likely lead to the end of the party’s 46-year existence.

The Macron political “Revolution” — the title of his most recent book — would then be complete: after defeating the two big parties, he would have destroyed them.