There was a time, not long ago, when the far-right leader Marine Le Pen wanted to get rid of France’s upper chamber. In 2014, she declared “there is an inflation of elected representatives and I’m no longer quite sure what purpose the Senate serves”, before adding: “I don’t see the democratic advantage of keeping it”.

But last week, Le Pen changed her tune radically. Perhaps because her National Rally (RN) party has finally gained a foothold in the Senate, she now sees the point of it. “Our senators will be an essential relay in the presidential campaign,” she said, jubilant. The Senate, it turns out, could help consolidate Le Pen’s hold on the country and her efforts to reshape French politics.

Last weekend, half the Senate was renewed. It is elected indirectly by an electoral college made up mostly of local councillors such as mayors and serves a six-year term, with half the seats up for grabs every three years. For the first time, the far right won enough to form a parliamentary group.

The National Rally more than quadrupled its presence, from three to 14 senators, and will sit as a group among the 348-member chamber. It was a notable step for French far right, coming just months before presidential elections where Le Pen will vie to be the successor to Emmanuel Macron.

The far-right party only entered the Senate for the first time in 2014, with three seats.

On the same night, Jean-Luc Mélenchon’s far-left France Insoumise (France Unbowed) party won its first seat. The extremes are knocking at the door, and this is precisely the point. Le Pen has vowed to get the Senate to harden its views.

For those watching France ahead of the presidential elections in April 2027, the signs are ominous. It also comes after recent German elections saw the far-right Alternative für Deutschland (AfD) party win big, putting the rest of Europe, including Andy Burnham, on notice.

Le Pen’s party already boasts the largest number of seats at the National Assembly, after Macron called ill-advised snap elections in June 2024.

But the Senate is different. Ever since 1958 and the beginning of the Fifth Republic, the Senate has been a bastion of the centre and centre right, with one exception, from 2011 to 2014, when the left held the majority.

Fourteen senators may not sound like much, but their power of disruption is real, especially in the lead up to the presidential elections, in which Le Pen is the front-runner.

The Senate offers a second reading of all bills, and its president is the second highest constitutional figure in France, replacing the country’s president should he or she become unable to serve. A parliamentary group in the upper chamber brings speaking time, staff, funds, a weekly question to the government and the ability to launch inquiries.

There is also fear that, sooner or later, some senators on the right will start cosying up to the National Rally, either in their votes or by forming an alliance. Success has a way of attracting people.

Gérard Larcher, the president of the Senate, may hope the upper house will remain “the chamber of calm debate, reason and reflection”, but many are asking how long that can last. The next six months will act as an accelerant.

Poll after poll now puts Le Pen ahead. In fact, she appears to strengthen her lead with each new survey, despite the Paris Court of Appeal confirming in July her conviction for embezzling more than €4m (£3.4m) of EU funds for her party’s financing.

According to the latest Harris poll, she is expected to win around 35-36 per cent of the vote in the first round of the election. If facing the far-left leader Mélenchon in the run-off, she would then crush him with 69 per cent of the vote, according to the poll. If up against Macron’s former prime minister, Edouard Philippe, she would still win with 57 per cent.

For now, other contenders from right to left are struggling to exist, or make their voices heard. Among them is the young and ambitious centre-left Gabriel Attal, only 37 and already a former prime minister, who recently launched the idea of a “United States of Europe”.

On the right, Bruno Retailleau, a former interior minister and leader of Les Républicains, has yet to make any impact. On the left, social democrat Raphaël Glucksmann has tried hard to gain momentum, without much success. According to polls, none of them would score more than 13 per cent in the first round.

For the moment, the presidential election looks like Le Pen’s to lose, which should make the UK, Brussels and the rest of Europe jumpy. With pro-Russian views and ties, Le Pen as president would send shivers through France’s eastern neighbours and Ukraine. On an economic level, a prolonged confrontation with markets and EU institutions could also force a painful fiscal adjustment and more broadly paralyse European decision-making at a key moment. 

Ultimately, this could force France’s more central parties to regroup in the coming months, under the banner of Philippe, the only non-extremist candidate who could hope to reach the second round. If not, France will be left with an impossible choice between a far-right and a far-left populist. Then the Senate’s cherished calm may not be the only thing under threat.