PARIS (Reuters) - French presidential favorite Emmanuel Macron came under fire from both potential allies and his run-off rival Marine Le Pen on Tuesday for acting as if victory next month was already in the bag.

FILE PHOTO: Emmanuel Macron (C), head of the political movement En Marche !, or Onwards !, and candidate for the 2017 French presidential election, leaves his home surrounded by policemen in Paris, France, April 24, 2017 the day after the first round of presidential elections where Macron ended in first place in front of the National Front party candidate. REUTERS/Benoit Tessier

Macron’s visit to a Left Bank brasserie on Sunday night after his first round triumph in particular handed ammunition to his opponents who described it as shallow, arrogant behavior.

Macron, a 39-year old former investment banker, pipped the National Front candidate to first place on Sunday and opinion polls see him comfortably beating Le Pen on May 7 to win the keys to the Elysee.

He took to the stage to thank his supporters in a 15-minute speech with his arms held aloft in a V for victory before going on with aides and a few celebrities to La Rotonde brasserie.

“They were patting themselves on the back with the whole celeb crew,” Le Pen remarked while visiting a wholesale market near Paris on Tuesday. “It shows that this arrogant cast thinks it’s already won and can do what it wants with the country.”

A centrist who has never held elected office, Macron would be France’s youngest ever president. He was silent the day after voting, leaving the field open to Le Pen who canvassed support in northern France where unemployment is high.

She attacked Macron for being “weak” in the face of terrorism, days after an Islamist militant killed a policeman on the Champs Elysees boulevard.

Speaking after President Francois Hollande warned earlier in the day against taking victory for granted, Macron said he was more determined than ever to beat Le Pen.

“Some have woken up with a hangover because Le Pen is there. I haven’t,” Macron told reporters after his first campaign trip since Sunday.

“Nothing is won. If things were won, we would not have seen how other elections turned out. I have never considered one minute that it was won. My battle is to defeat Marine Le Pen.”

Political leaders from France’s two shell-shocked mainstream parties on the right and left have endorsed Macron, including the unpopular outgoing Socialist President Francois Hollande and defeated conservative candidate Francois Fillon.

Yet perceptions of complacency could pose a big risk to Macron’s Elysee bid. Pollsters say a low turnout would favor Le Pen.

Political analysts have contrasted Macron’s actions and those of ex-president Jacques Chirac in 2002 when Jean-Marie Le Pen, Marine’s father who founded her National Front party, shocked the establishment by reaching the second round.

On that occasion, Chirac issued a grave five-minute statement. He went on to beat Le Pen senior in a landslide run-off vote.

“He (Macron) was way off the mark, as Charles de Gaulle once put it,” said Jean-Christophe Cambadelis, head of the Socialist party, referring to the post-war leader’s self-criticism for not seeing the significance of the 1968 student riots.

“FALSE START”

“I haven’t found the first 48 hours of the democratic candidate to be up to the job of fending off her attacks,” Cambadelis said.

Others accused Macron of hubris.

The left-leaning Libération newspaper said Macron “already sees himself there”. The financial daily Les Echos said he had made a “false start”.

Many compared Macron’s dinner at La Rotonde, an elegant brasserie favoured by artists such as Ernest Hemingway before the war, to former president Nicolas Sarkozy’s victory celebration at the upscale Fouquet’s restaurant in central Paris in 2007.

Those images gave ammunition to Sarkozy’s opponents who portrayed him as the “bling-bling” president, an image that stuck throughout his mandate.

“The Rotonde was a mistake,” Dominique Wolton, a political communication specialist at French research institute CNRS. “It’s extraordinary that they repeated the Fouquet’s mistake again.”

Macron’s team went out on morning radio shows on Tuesday to try to put out the volleys of criticism.

“After months and months of work and canvassing, it was normal that our candidate salute all the militants who supported us,” said Richard Ferrand, head of Macron’s political movement.