Brussels' next top official Ursula von der Leyen set out an ambitious plan for a green and digital transformation of the EU economy Wednesday, as she urged MEPs to approve her top team.

The 61-year-old conservative takes office with Europe challenged to find its new role in a dangerous world, and with Brussels' power undermined by Franco-German rivalry and Britain's imminent exit.

But, addressing the European Parliament in Strasbourg, the former German defence minister endeavoured to strike an upbeat note, urging lawmakers to approve her 27-strong commission so that she can get to work on December 1.

"I ask for your support to give Europe a new start," she said, in a largely well-received speech attended by the massed ranks of the nominated commissioners and in which she shifted fluently between English, French and German.

"Our union will embark on transformation that will touch every part of our society and economy and we will do it because it will be the right thing to do, not because it will be easy," she said.

Hailing the Dutch vice-president that she was obliged to pick as her deputy by EU member states, socialist Frans Timmermans, as the right man for the dossier, she promised a "European green deal... for the health of our planet, our people and our economy."

As well as promising measures to combat climate change, von der Leyen insisted that Europe has the heft to lead the world in a digital economic revolution.

Von der Leyen plans green and digital transformation
Von der Leyen has to contend with growing divisions between German Chancellor Angela Merkel and French President Emmanuel Macron. Photo: AFP / Pascal PAVANI

"We are the world's trading superpower," she boasted. "We are the largest source and destination of foreign direct investment anywhere in the world.

"We should harness this twin power of digitalisation and climate transition to boost our industrial base."

Von der Leyen can expect to see her commission approved, but her own appointment to succeed Jean-Claude Juncker as president was approved in July with only nine votes more than she needed, a narrow margin in EU politics.

Three of her initial nominees to the commission were rejected during the parliamentary confirmation process -- an unprecedented snub -- weakening her from the outset.

Nevertheless, EU diplomats and parliamentary leaders are cautiously optimistic she will clear Wednesday's hurdle, a public vote of MEPs at 12:30pm (1130 GMT).

"Our priorities are a crucial part of the von der Leyen commission," said Manfred Weber, head of the parliament's centre-right EPP bloc and himself a disappointed former presidential hopeful.

"In 2024 Europe will have the most ambitious and inclusive climate policy in the world, a European border and coast guard, transformed Europol into a European FBI, a master plan to fight cancer and created millions of jobs."

The July vote to confirm von der Leyen was conducted by secret ballot, allowing many MEPs to vote against her in protest at the EU leaders' political tactics.

The conservative takes office
After much wrangling, the executive team of incoming European Commission President Ursula von der Leyen will be put to final vote. Photo: AFP / Kenzo TRIBOUILLARD

But Wednesday's roll-call to approve the commission as a whole will be conducted openly, helping the main centre-right, social democratic and liberal factions to whip support.

The commission has members from across the political spectrum and 12 out of 27 of the members will be women, not quite the parity that was promised but the highest number ever in the European Commission.

There will nevertheless be opposition. The parliament's eurosceptic, far-left and right-wing populist parties will vote against, and the sceptical Greens have said they will abstain.

"Having heard the von der Leyen speech in the European Parliament today, I already miss Juncker," sighed German MEP Reinhard Buti Kofer. Five French socialists will also sit on their hands.

And there is one more potential cloud hanging over the investiture: the absence of a British commissioner.

Prime Minister Boris Johnson plans to pull Britain out of the EU on January 31, after Brexit was repeatedly delayed amid wrangling in Westminster over the divorce terms.

But in the meantime he has refused to fill Britain's seat on the commission and is now standing for re-election in a December 12 vote.

Von der Leyen expressed regret at Britain's decision and was markedly more conciliatory than her predecessor Juncker, who often made jokes about what he saw as London's great mistake.

"I have made no secret that I will always be a remainer. But I will also always respect the decision taken by the British people," she said.

"And whatever the future holds, the bond and the friendship between our people are unbreakable."

Copyright AFP. All rights reserved.

John refused to fill Britain's seat
Prime Minister Boris Johnson has refused to fill Britain's seat on the European Commission. Photo: AFP / Daniel LEAL-OLIVAS