If von der Leyen fails - and the vote could be close - then then European Union faces a summer of institutional infighting between parliament and the bloc's 28 leaders.
Calling the prospective future European Commission president's candidacy "an affront to the allegedly transparent EU-democracy", he added: "If anyone in the European Parliament wants to destroy the EU - he should vote for her".
The Christian Democrat of the European People's Party was a last-minute candidate to succeed Jean-Claude Juncker that EU leaders agreed as part of a package of top jobs that were decided on early this month.
But despite her promises for greater gender equality, von der Leyen did not mention abortion or LGBTi rights in her opening speech.
As family affairs minister, she fought to overhaul parental leave policy to encourage fathers to also take time to care for their children.
The election of Mrs von der Leyen by the European Parliament came as Boris Johnson sent tremors through Westminster by significantly hardening his Brexit demands by rejecting either a time-limit or a unilateral exit mechanism to the Irish backstop as insufficient to satisfy MPs.
Representatives from the governing parties in Hungary and Poland criticised Von der Leyen's pledge to continue with the commission's attempt to block or reverse judicial changes in their countries.
A life-long high achiever, von der Leyen has at times drawn envy and animosity for her best-in-class style, the persona of a super-mum with iron discipline and a ideal hairdo that some voters find unnerving. Their co-chairman Ska Keller said there had not been enough "green content" to her proposed green deal. "Your confidence in a united and strong Europe, from east to west, from south to north", said the German conservative, who earlier this week resigned as Berlin's defence minister.
"Exactly 40 years ago, the first president of the European parliament, Simone Veil, was elected and presented her vision of a united Europe", Von der Leyen said.
She added that von der Leyen had to tread a fine line to keep the large consensus she needs without alienating her own conservative group, the EPP, which has not committed to the 55% target.
"I do not want a Europe where there are new and old members - those with more and those with less of a voice", Kaljurand said, speaking in Estonian.
After returning to Germany, von der Leyen got involved in local politics.
She told MEPs this morning that her view on Brexit is that it was a "serious decision" of the British people and "we regret it, but we respect it".
In a vote on Tuesday afternoon Ms Von der Leyen won with 383 votes to 327 with 22 abstentions.
The Withdrawal Agreement negotiated with Theresa May's administration by Michel Barnier "provides certainty where Brexit created uncertainty", she said.
"Her expertise in defence and security issues make her an appealing candidate for France, which is advocating a deepening of integration in this area, as well as many Eastern European governments".
"However, I stand ready for a further extension of the withdrawal date should more time be required for a good reason".
The European Parliament will hold committee hearings in September to grill commissioner nominees, such as Ireland's Phil Hogan, and judge if they are up to the task.