PARIS >> Freshly elected to the French presidency, Emmanuel Macron now faces an equally difficult Act II: securing the parliamentary majority he needs to make good on his campaign promises to lift France out of economic gloom.

With legislative elections just five weeks away, the start-up political movement the 39-year-old former investment banker launched one year ago on his meteoric ride to become France’s youngest president lost no time Monday in girding for the crucial mid-June election battle.

Without a working majority, Macron could quickly become a lame-duck president, unable to push through labor reforms and other measures he promised to the broadly disgruntled electorate — shown by a record result for his defeated far-right opponent, Marine Le Pen, and a record number of blank and spoiled ballots in Sunday’s runoff vote.

The transfer of power to Macron will take place Sunday, outgoing President Francois Hollande announced. Macron is already looking the part. He shed his breezier campaign demeanor for a solemn, more statesman-like look in his first appearances after his victory and again Monday, at a sober ceremony with Hollande to commemorate Germany’s defeat in World War II.

The pomp of the ceremony, at the imposing Arc de Triomphe at the top of the Champs-Elysees Avenue in Paris, immediately helped lend a presidential air to the previously untested leader who fought and won his first election.

It was the first time Hollande and Macron appeared together in public since August 2016. That was when Macron resigned as Hollande’s economy minister to embark on his risky presidential run as an independent — a decision received coldly by the French leader at the time.

On Monday, though, Hollande gripped Macron’s arm before the two men walked side by side. The ceremony marked decades of peace in Western Europe, something Macron made a cornerstone of his campaign against Le Pen’s brand of nationalist populism. Le Pen campaigned for France to leave the 28-nation European Union and drop the shared euro currency in favor of reinstating a new French franc.

Yet to move into the presidential Elysee Palace, Macron is already preparing his first days in power. Sylvie Goulard, a French deputy to the European Parliament, said Macron would make Berlin his first official visit, with perhaps a stop to see French troops stationed abroad as well.

Macron’s optimistically named “En Marche!” — “On the Move” — political movement plans to field candidates for all 577 National Assembly seats. But it will be contesting its first ever election. As part of his effort to convince voters that both he and his movement marked a break with the status quo, Macron previously promised that half of its candidates will be new to elected politics. That means many of them may be burdened by the handicap of being largely unknown to voters in constituencies they compete for.

Split 50-50 between men and women, they’ll have Macron’s example for inspiration: Contesting his first election, he handily beat Le Pen with 66 percent of Sunday’s vote and tore up France’s political map.

But Le Pen’s 34 percent — a high in any national election for her far-right National Front — confirms her party as a formidable force, its French-first nationalism increasingly accepted by a growing swath of electors despite its history of anti-Semitism and racism. The National Front has two lawmakers in the outgoing parliament but hopes for dozens in June.

Mainstream parties on the left and right that were frozen out of Sunday’s runoff in a first for modern France, also are regrouping, aiming to clip Macron’s wings and impose their political agenda, via parliament, on his five-year term.

Macron will name his prime minister next week, but could be forced to amend his choice if the legislative elections don’t go to plan. The worst-case scenario for him would be a strong parliamentary majority for his opponents, dictating his choice of prime minister and limiting his presidency. That fate befell conservative President Jacques Chirac when the left secured a majority in legislative elections in 1997, saddling him with Socialist Prime Minister Lionel Jospin for the next five years.

Macron’s movement is banking that voters, having elected him, won’t want to see his presidency hobbled so quickly. But that is far from guaranteed. Many voters backed him reluctantly, simply to keep out Le Pen’s extremism. Macron can’t count on their loyalty.

A protest Monday in Paris against Macron’s planned reforms drew several thousand people. There were brief clashes with police and several arrests.

“He needs to cool down,” said Raphael Garine, a protesting student. “If he wants to continue the reckless policies of the past five years we will take to the streets to demonstrate.”

In the Paris metro, a defaced advertisement captured the mood. “Macron: Not even started, already hated,” it read. Overnight Sunday, police arrested 141 people in eastern Paris in clashes with masked protesters.

Macron’s movement announced Monday that it was rebranding itself with a new name, “Republic on the Move.” Macron also resigned as its president, as he takes on his new role as president of the republic. Announcing the changes, the movement’s secretary general, Richard Ferrand, said the organization will be “a new political force” on the landscape redrawn by Macron’s victory. It will release its list of 577 candidates on Thursday.

Le Pen says the 10.6 million votes she won on Sunday will make her party the leading opposition. The National Front is also gearing up for a rebranding — if not a makeover — of its ideas. In interviews Monday, party officials said a new name would aim to broaden its appeal.

More congratulations rolled in from world leaders. U.S. President Donald Trump called to congratulate Macron, while on the Kremlin website, Russian President Vladimir Putin urged Macron to “overcome mutual mistrust and unite to ensure international stability and security.”

In Britain, Prime Minister Theresa May said Macron’s win makes it even more important for British voters to back her Conservatives in the early election she called for June 8, to strengthen Britain’s hand in its divorce proceedings with the EU.

Market reaction Monday to Macron’s victory was subdued: investors were expecting it and seem wary of the difficulties he faces.

The CAC 40 index of leading French shares fell 0.9 percent to 5,383. Other indexes across Europe also dipped, while the euro, which briefly hit a six-month high above $1.10 overnight, was down 0.7 percent at $1.0924.