STRASBOURG — After months of feuding, pro-EU parties lined up behind the new European Commission on Wednesday — with one notable exception: the Greens.

The vast majority of the Green group — the fourth-largest bloc in the European Parliament — abstained in the vote that gave Ursula von der Leyen's team the all-clear to take office on December 1.

The Greens' decision to keep the new EU executive at arm's length risks excluding the party from important legislative decision-making just as their signature issue has risen to the top of the European political agenda.

Their opponents within the pro-EU mainstream attacked the party for failing to get on board with the new Commission, when the center-right president-elect has pledged to put action to tackle climate change at the heart of her platform.

But Green MEPs argued that they can drive a harder bargain with the Commission and EU governments by showing they won't lock themselves in to an overarching alliance with mainstream rivals for the next five years. Above all, the party wants the EU to go further and faster when it comes to curbing carbon emissions and fighting climate change. For Greens, von der Leyen's aim of making the EU carbon-neutral by 2050 is not ambitious enough

Empowered by strong electoral showings and mass demonstrations by young climate activists across Europe and around the world, the Greens say they feel powerful enough to make an impact on the European stage without having to commit their votes as a part of a pro-EU majority coalition.

"We have sent a yellow card to the Commission, which aims to say, 'It's not fine, things are starting badly,'" said Yannick Jadot, a senior French Green MEP. "We can't give a green light to this Commission, which has refused all the help the Greens offered" on agriculture, climate, trade and the rule of law after May's European election, he said.

"I objectively don't understand the position of the Greens group on this Commission" — MEP Stéphane Séjourné of the Renew Europe group

The group's stance is in marked contrast to some of the Continent's most prominent Green parties. Germany's Greens have served in national government and have made clear they are eager to do so again, as they have surged in opinion polls in recent years. Austria's Greens are in talks to join conservative leader Sebastian Kurz in a coalition government.

The group's position also stands out when compared to other pro-EU blocs in the Parliament, who helped torpedo some of von der Leyen's nominees and sought to extract concessions from her before falling into line for Wednesday's vote.

And it left the Greens open to accusations of abdicating their responsibility at the very moment they are needed to help save the planet from environmental catastrophe.

Stéphane Séjourné, head of the French delegation of the centrist Renew Europe group, accused the Greens of not supporting "the most progressive and most environment-friendly Commission" in history.

"I objectively don't understand the position of the Greens group on this Commission," he declared in the debate before the vote on von der Leyen's administration.

Daniel Caspary, head of the German delegation of the center-right European People's Party (EPP), also took a jab at the Greens. "The first female Commission president, 11 female commissioners and a 'Green Deal' — and still it's not good enough for the Greens in the European Parliament," he tweeted. "Compromise seems to be a one-way street for the Greens."

Dissent in the ranks

Even within their own bloc in the European Parliament, not everyone agreed with the decision to withhold support from von der Leyen. The Scottish National Party's three MEPs, who are part of the Greens/European Free Alliance group, broke ranks to vote in favor of the new Commission.

"We want Scotland to remain within our European family of nations and we want to play a constructive part," said SNP MEP Alyn Smith. "Where we might take issue with the process that got us here, we think it important to approve the commissioners so they can get on with their work."

But Green leaders made clear they were not closing the door on von der Leyen and would consider whether to work with her Commission on a case-by-case basis.

"Are we going to be their allies, play the role of socialists, replace them, be 'yes-men' and never saying anything? The answer is no" — French Greens MEP Marie Toussaint

"The Greens will send a single message to the Commission, which is to say, 'Come with something to offer, come with legislation ... if these go in the right direction, we are ready to follow, and if not, we will stand in your way,'" Philippe Lamberts, the co-leader of the Greens/EFA group, told reporters on Tuesday.

Jadot, the French MEP, declared that "the Greens will never place themselves outside of the process of policy-building."

"We're not here to comment on policies, we're here to make them," he added.

And other pro-EU groups, acutely aware of how big environmental issues are for voters at the moment, made clear they are still willing to work with the Greens.

Iratxe García, leader of the center-left Socialists & Democrats group, said her bloc is "looking forward to working with the Greens, with whom our group shares many important goals." She said the two would continue to cooperate "in many important areas, such as migration or social rights," as they did in the past.

For some Greens, however, the social democrats serve as an example of the dangers of cooperating too closely with the long-dominant EPP.

"Are we going to be their allies, play the role of socialists, replace them, be 'yes-men' and never saying anything? The answer is no," said Marie Toussaint, a French Green elected to the Parliament in May. "What they propose to us is overall status quo, but sprinkled with some additional efforts on gender-parity in the Commission, and on emission targets."

Toussaint made clear she felt little affinity with other mainstream parties, which she portrayed as out of touch with young people and everyday life. "The vast majority of the Parliament relies on a very outdated mindset," she said.

Greens have presented von der Leyen's Green New Deal as a collection of good intentions that falls short on policy commitments. They also complain that no one from a party in their group was nominated to serve in the new Commission.

"It was the choice of the three big groups to do as they always do — share the jobs between themselves," Jadot said.