The Greens will exact a high price for backing German conservative Ursula von der Leyen as European Commission president, judging by their first encounter.

The environmentalist party's two top MEPs, Ska Keller and Philippe Lamberts, damned the German nominee with faint praise Monday, on her first attempt to secure their votes for her surprise candidacy for the EU's top job.

The German defense minister came across as "a very able politician," Keller told reporters afterward. "But from my own point of view, that's not enough."

Unlike von der Leyen, who emerged from last week's emergency EU summit as the compromise candidate to succeed Jean-Claude Juncker as Commission president, Keller was a Spitzenkandidat — one of the "lead candidates" who would supposedly compete for the job in a democratic contest.

The Greens made significant gains in May's European election and their policies — especially on climate change — resonate deeply among young EU voters.

The Greens are "very disappointed" at the European Council's decision to kill that process, Keller said. "Now we end up in the situation where the Council comes up with someone no one had on their piece of paper ... So for us, this is really a major problem because it's a step back in democracy."

For von der Leyen, who hails from the center-right European People's Party, to win an absolute majority in the European Parliament confirming her in the post, the backing of Greens is crucial, given the opposition of many Social Democrats. If the Parliament rejects her, the Council has a month to submit another nominee.

Von der Leyen needs the backing of at least 375 MEPs at next Tuesday's plenary vote in Strasbourg. The full backing of the three largest groups — the conservatives, Socialists and liberals — would secure her 444 votes. However, given the likelihood of defections and holdouts, she would welcome support from among the 74 Green MEPs as a cushion — and a boost to her democratic mandate.

“This was a tough meeting. She is clearly searching for the Green support, but not sure she can find a substantiated balanced approach in one week,” said Dutch Green MEP Bas Eickhout, Keller's co-Spitzenkandidat. “This just shows why the [lead candidate] process is so important. It offers an entire campaign to know where someone stands.”

The meeting with the Green leaders is part of a rushed charm offensive among MEPs that von der Leyen began almost immediately after she emerged as the unexpected compromise candidate, in place of fellow German conservative Manfred Weber who was blocked by France's Emmanuel Macron, among others.

She meets the full group of Green MEPs later this week, as well as MEPs from the Progressive Alliance of Socialists and Democrats and the centrist-liberal Renew Europe group.

Green ambition

EU leaders nominated von der Leyen for the Commission presidency last Tuesday in a package that included Belgian Prime Minister Charles Michel to head the Council (which gathers EU national leaders), Christine Lagarde (who runs the International Monetary Fund) as president of the European Central Bank and Spanish Foreign Minister Josep Borrell as EU foreign policy chief.

Since her nomination, von der Leyen has posted several tweets but avoided any public statement, and has not taken any questions from the press. That pattern continued on Monday at Egmont Palace in Brussels where she met Michel, with photographers invited to take pictures of her arrival.

"Mrs. von der Leyen, it has been a week since you were appointed, do European voters deserve to hear more than tweets?" a POLITICO reporter shouted as she entered the building. Von der Leyen did not even turn her head.

After the meeting, Michel issued a statement saying they "discussed the future priorities of the European Union."

"Europe is facing huge challenges in the coming months such as Brexit, the next European budget and climate change," the statement added. "Ursula von der Leyen and Charles Michel agreed that European institutions will have to work in close cooperation to address these issues."

To get to that stage, there's a whole lot of Green reservations to overcome first.

The Greens don't head any national government in the EU and were therefore not part of the leadership deliberations among EU national leaders. However, they made significant gains in May's European election and their policies — especially on climate change — resonate deeply among young EU voters.

Last week, European Council President Donald Tusk told parliamentarians in Strasbourg he backs the idea of a Green candidate for a Commission post.

“I am fully confident that cooperation with the Greens and their presence in the EU decision-making bodies will benefit not only the governing coalition, but Europe as a whole,” Tusk said at a plenary session on Thursday.

Tusk promised to “appeal to all my partners to involve the Greens in the nominations, even though there is still no European Council leader from this party. I hope that the newly nominated Ursula von der Leyen will also listen to my appeal, in fact, I will pass her this message directly later today.”

'Content demands'

One way to overcome the Greens' complaints about the selection process may be to offer them policy concessions and top-level representation — including, potentially, a Green commissioner. Or, as Keller put it: "Green people in positions who can carry out the implementation" of their policy program.

Von der Leyen's talks with Keller and Lamberts Monday didn't include any "specific program proposals," Keller said. "That will come later."

One sticking point — apart from the veteran German Cabinet minister's lack of historic support for (or opposition to) environmental goals — is the failure of von der Leyen's EPP to back boosting the EU’s 2030 emissions reduction goal.

According to a draft document seen by POLITICO that lays out where the parliamentary groups have managed to find agreement, the goal of increasing the current 40 percent goal to 55 percent is supported by the Greens, S&D and RE, but not the EPP. The EPP is also a holdout on phasing out of fossil fuels, the future of the Common Agricultural Policy, and the recalling of polluting cars.

“The Greens want von der Leyen to come up with names and compromise on content,” said Eickhout, the Dutch Green MEP. “She knows what our content demands are and she can figure out what we need in positions.”