If you just look at the headlines of the British and French elections you would never know just how important the political left factored into these elections.
In Britain, the Labour Party had an overwhelming victory over the Tory Party. However, it wasn't so much a victory for Labour as it was a defeat for the Tories.

The absolute number of votes cast for Labour was lower than it was in 2019. If we take account of the fall in turnout, Keir Starmer added less than 2 percent to the party’s 2019 vote share. Labour’s final score, 33.7 percent, was well below the average vote share for Labour under Jeremy Corbyn’s leadership, let alone the 40 percent it took in 2017. Yet Starmer has won a landslide majority of seats in the House of Commons, thanks to a Conservative meltdown and Britain’s winner-takes-all electoral system.

As the polling expert John Curtice put it, “This looks more like an election the Conservatives have lost than one Labour has won.” The Tory vote share dropped by 20 percent...

From day one, this has been the kind of outcome Starmer and his team were hoping for. They never wanted to take office amid a surge of enthusiasm with an ambitious reform program to address Britain’s multifaceted social crisis. Their goal was to make Labour completely inoffensive to all those who benefit from a dysfunctional economic model.

A record 11 former Tory cabinet members have lost their parliamentary seats. If the British public rejected the Conservatives in 2017 or 2019 in the same way they did yesterday, Corbyn’s Labour would have secured a victory as big as the one we are witnessing today.
Labour won after purging the entire left from the party. What remains of the party is a center-right neoliberal party that effectively has promised the working class nothing. It's a pretty safe bet that in five years the people will be tired of a ruling party that does nothing but NOT be as terrible as the people that came before.
It's a far different party than the one under Corbyn, which at one time boasted the largest membership of any party in Europe.

Meanwhile in France, Macron's center-right party continues to pay the price for his disrespect of the left.

Two months on, the ruling party has singled out the veteran leftist and his fledgling coalition as the new threat to the Republic. It has portrayed the NUPES as another extremist outfit – in the words of Macron’s former education minister Jean-Michel Blanquer, an extreme “just as dangerous as [Le Pen’s] far right”.

It’s a narrative that fits well with Macron’s moderate constituency, says Jean-Yves Dormagen, a professor of political science at the University of Montpellier and the head of polling institute Cluster17.

“What binds together Macron’s camp, more than a political project, is a rejection of extremism, of populism, of figures deemed too radical and extreme, like Mélenchon or Le Pen,” Dormagen said. “When Macron presents himself as the head of the ‘republican camp’, of the party of order and stability, he highlights that which underpins his electoral coalition: namely a desire for good governance, stability, order and the status quo,” he added. “That’s the cement holding together his support base – a coalition of centre-right and centre-left voters who disagree on most other issues.”
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The next day, Montchalin appealed “to all republicans” to hold off the “far-left anarchists” who “promise disorder and submission for France”. Speaking on CNews, she framed the election as a “referendum for Europe and against disobediance, a referendum for order and against street disorder”, seemingly unfazed by the fact that her opponent, veteran Socialist Jérôme Guedj, hardly qualifies as a radical.

Her cabinet colleague Clément Beaune, the junior minister for Europe who is locked in a tight race in Paris, focused his attacks on members of Mélenchon’s party, warning that “all NUPES lawmakers, particularly those coming from La France insoumise, will be a source of agitation and provocation (…) and won’t work for the benefit of the country”.

When Macron called the election he expected that fear of the far-right would cause the left to fall in behind him, despite his contempt. Well, they didn't. Suddenly Macron discovered just how little support he had.

“Jean-Luc Mélenchon pulled off an extraordinary PR coup,” said Pascal Perrineau, a professor of political science at Sciences-Po Paris. “Asking the French to elect him prime minister might sound absurd, but it was an extremely shrewd strategy. It allowed him to both supplant Le Pen as Macron’s chief opponent and cast himself as the pillar of a revamped left.”

The PR stunt was soon followed by another tour de force, which even critics have hailed as a masterstroke. In the days following Macron’s re-election, Mélenchon and his team engineered what many had come to see as an impossible feat: a broad alliance of France’s deeply fractured left, united around a common policy platform and fielding a single candidate in each of France’s 577 constituencies.

The far right is divided, Le Pen has shown little appetite for legislative elections, the mainstream right is virtually inaudible, and Macron’s camp has precious little to say aside from attacking Mélenchon – which is a bit thin for a political platform,” said Michel Wieviorka, a sociologist and professor at the École des Hautes Études en Sciences Sociales (EHESS).

Unlike Macron's center-right party, Melenchon's party actually promises things for the working class.
So now, too late, Macron is finally ready to make some deals with the left in order to keep Le Pen from wining an absolute majority.