With less than two weeks to go before the first round in the snap elections called by Macron in response to the far right drubbing his party in European polls, the president's party is trailing badly.

Opinion polls forecast his ruling alliance would come third in the legislative elections on June 30 -- followed by a second round on July 7 -- behind the far-right National Rally (RN) and a new left-wing alliance.

This could make RN leader Jordan Bardella prime minister in an awkward "cohabitation" with Macron, although the 28-year-old has insisted he will only accept this if his party and allies win an absolute majority of seats.

Visiting a major defense show outside Paris, Bardella insisted he does "not plan to question the commitments France has made on the international stage" on defense if he takes power.

He added that France would keep up weapons deliveries to Ukraine under an RN government -- although long-range missiles and other arms that could hit Russian territory would be ruled out to "avoid any escalation risk".

"Our credibility towards our European partners and NATO allies is at stake," he said at the Eurosatory arms trade show, moderating the far right's historic hostility to the US-led alliance.

Opponents have long pointed to a massive loan the RN received from a Russian bank in 2014, which it has since repaid, and the past warm relationship between its figurehead Marine Le Pen and the Kremlin.

The emergence of the New Popular Front (NFP), which groups left-wingers from Socialists to Communists, has been an unwelcome development for Macron since he called the snap elections in the hope of rallying moderates across the spectrum.

Former conservative prime minister Dominique de Villepin gave the left-wing alliance indirect backing on Wednesday, saying the priority was fighting the RN in the second round.

But Macron on a visit to western France on Tuesday said that he had "confidence in the French" not to choose either extreme: left or right.

"The RN and its allies offer things that may make people happy but in the end we are talking 100 billion (euros) a year" ($107 billion) in unbudgeted costs, he said.

Bardella has tried to shore up his economic credibility by soft-pedalling costly promises including slashing VAT on energy and fuel.

Prime Minister Gabriel Attal dismissed the RN's stance on Wednesday, comparing its proposals to an "onion" and calling it a party of opposition.

"Every day, the program peels and at the end the only things left are your eyes crying, because it's not serious, it's not credible," he told broadcaster TF1.

France's public debt of 110 percent of GDP -- more than three trillion euros -- was back in focus on Wednesday with the European Commission opening an excessive deficit procedure against Paris.

Macron had on Tuesday also lashed out at the NFP, charging that "with the extreme left it's four times worse" than the far right.

"There is no more secularism, they will go back on the immigration law and there are things that are completely farcical like changing your gender at the town hall," he said.

The left-wing coalition's program includes a proposal allowing the change of civil status.

Anti-discrimination groups rejected the comments, with SOS Homophobie accusing the president of "transphobia".

"How is it possible that this man who was elected and re-elected to confront the extreme right is in reality repeating the discourse of the extreme right?" Socialist Party chief Olivier Faure told RTL radio network.

The fight against anti-Semitism was at the center of the campaign on Wednesday after two boys aged 13 were charged with the rape motivated by anti-Semitism of a 12-year-old Jewish girl outside Paris.

Macron told a cabinet meeting that the "scourge of anti-Semitism" was threatening French schools and called for "dialogue" about racism and hatred of Jews in classrooms.

France experienced a surge in anti-Semitic acts after Hamas's October 7 attack on southern Israel and the start of Israel's retaliatory campaign in Gaza.

Strongly pro-Palestinian and regularly accused of anti-Semitism by opponents including Macron, hard-left LFI's former presidential candidate Jean-Luc Melenchon tweeted that he was "horrified" by the attack.

Meanwhile Marine Le Pen -- whose party was co-founded by a former member of the Nazi Waffen SS paramilitary -- said the gang rape "revolts us", accusing the "extreme left" of using the Israeli-Palestinian conflict for political ends.