Candidates in France's looming presidential election are pushing to make themselves heard over the war in Ukraine, as polls suggest incumbent Emmanuel Macron remains the clear favourite to win.

Buoyed by his shuttle diplomacy and toughness on Moscow since its troops invaded Ukraine, the president is riding high with two weeks to go before polling, but has faced accusations of ducking real debate.

Questioned Sunday on his meagre campaigning, a testy Macron told broadcaster France 3 that "no one would understand at a moment when there's war" if he was out electioneering "when decisions have to be made for our countrymen".

Short of a major upset at the April 10 first-round vote, Macron's opponent in the runoff will be far-right National Rally leader Marine Le Pen -- a repeat of five years ago.

Paris
Far-right candidate Eric Zemmour rallied thousands of supporters near the Eiffel Tower on Sunday Photo: AFP / BERTRAND GUAY

But her far-right rival Eric Zemmour, conservative Valerie Pecresse and left-winger Jean-Luc Melenchon still hope they can break out from the pack to reach the second round on April 24.

"Everything could be decided in the two weeks to come," with four in 10 likely voters still undecided, Adelaide Zulfikarpasic of the BVA Opinion polling group told AFP.

Former columnist and TV commentator Zemmour on Sunday rallied thousands waving French flags under a cloudless sky near the Eiffel Tower.

French presidential election
Main declared candidates for the French presidential elections. Photo: AFP / Erin CONROY

He urged more energy from his supporters after a speech hitting familiar notes of nostalgia for past French greatness and swipes at unassimilated immigrants.

"We've still got 14 days left, it's an eternity", Zemmour insisted, claiming to be "the only candidate on the right".

Now trailing below 10 percent in some polls, Zemmour is far short of Le Pen's roughly 20 percent and Macron at close to 30.

Le Pen strove to project serenity as allies -- including her niece Marion Marechal -- deserted her for the tougher-talking Zemmour.

Instead Le Pen has pounded the pavements campaigning on French streets and market squares, and on Sunday again sought to cast herself as more mainstream and competent than her rival.

Left-winger Jean-Luc Melenchon
Left-winger Jean-Luc Melenchon believes a last-minute surge can get him into the second round Photo: AFP / CLEMENT MAHOUDEAU

"Eric Zemmour's programme is brutal in form but very limited in substance, whereas I have a draft law ready to be passed" on Islam and immigration, she told weekly newspaper Le Journal du Dimanche on Sunday.

Senegal's ambassador to France meanwhile denounced Zemmour's "racism" after the candidate claimed during a visit to a drugs-hit part of the capital Friday that most of the dealers were Senegalese and should be deported.

With Zemmour and Le Pen slogging it out for the hard-right and Macron sounding pro-business and law-and-order notes, conservative Valerie Pecresse has struggled to make herself heard.

Most recently, a positive Covid test has kept her from planned campaign stops.

On Sunday, the leading left-wing candidate Jean-Luc Melenchon -- polling at 12 to 15 percent -- was rallying supporters in the Mediterranean port city Marseille.

While left-wing resistance including the 2018-19 "yellow vest" protest has dogged the presidency of former banker Macron, a slew of competing candidacies from the left have yet to make a real mark on this year's election.

Melenchon told the crowd that "we've suddenly said to ourselves 'we're going to make it'" into the second round.

"We're going to talk about serious things, not money fantasies like the one or racist fantasies like the other," he added, targeting Macron and Le Pen.

Left-wing voters are split between Paris Mayor Anne Hidalgo -- polling around just two percent for the once-mighty Socialist Party -- Communist candidate Fabien Roussel and Greens boss Yannick Jadot.

The woes of Pecresse and Hidalgo, candidates respectively of the traditional right and left bastions that dominated France for years, illustrate the longer-term factors beyond Ukraine that have scrambled French politics.

"Voters have a much more independent, individualised relationship to politics and to their electoral choices, they're much more mobile, more volatile," she said.

Especially given that "the majority of French people don't feel represented by political office-holders."

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