Marine Le Pen’s right-wing National Rally (RN) and an allied party have won enough seats in the French Senate to form a group for the first time. The breakthrough comes months before a presidential election in which polls currently put Le Pen in the lead.

RN and the Union of the Right for the Republic (UDR) will together hold at least 15 seats in the 348-seat upper house following Sunday’s vote. A group requires a minimum of ten members and gives its lawmakers a greater role in Senate committees, where legislation is examined.

“This is a historic victory, and a major milestone with the formation for the first time of a group in the Senate,” Le Pen wrote on X. She said the result showed the party gaining support across France and that its senators would carry the concerns of local communities into the presidential campaign.

Despite RN’s latest gains, the Senate will remain controlled by the conservative Republicans and their centrist allies.

RN president Jordan Bardella has nevertheless called the result a sign of the party’s momentum ahead of what he described as “the mother of all battles,” referring to the upcoming presidential election.

In July, the Paris Court of Appeals reduced Le Pen’s five-year ban on holding elected office over a misused funds conviction, clearing her to run in the 2027 race to replace Emmanuel Macron who will be leaving office after serving two terms.

A Toluna Harris Interactive poll published on Monday has placed Le Pen as the frontrunner at 35-36% in the first round and projected that she would defeat both left-wing France Unbowed leader Jean-Luc Melenchon and centrist former Prime Minister Edouard Philippe in hypothetical runoffs.

The RN breakthrough has drawn a hostile response from rival factions, including from Socialist Senate group leader Patrick Kanner, who said his party would work to contain the “chamber of horrors” entering the Senate.

Le Pen accused Kanner of “dishonoring himself” and insulting both the newly elected senators and the local officials who voted for them.

The prospect of Le Pen replacing Macron raised particular concerns among the Western backers of Ukraine. The Telegraph reported in August that officials fear her election could disrupt the French-led effort to coordinate military and financial support for Kiev, as well as plans to deploy Western troops there after a ceasefire.

RN has long challenged Macron’s approach to the Ukraine conflict, opposing open-ended funding for Kiev and steps it says risk a direct confrontation with Russia. Le Pen has repeatedly stressed that the conflict needs a diplomatic solution and has called for normalizing relations with Moscow.