Ursula von der Leyen, the nominee to lead the European commission, sought to build bridges with members of the European parliament in Strasbourg after a mixed reaction to her historic appointment.

Germany’s defence minister was a surprise choice to lead the commission, as EU leaders struggled to reach a compromise during three days of summit talks dedicated to finding people to lead the EU’s most important institutions.

Von der Leyen needs to win support from a majority of members of the European parliament in order to take over the reins from Jean-Claude Juncker on 1 November. She travelled to Strasbourg on Wednesday to meet MEPs from her centre-right political family, the European People’s party.

In that short meeting, she introduced herself to MEPs, speaking in her native German, as well as fluent English and French. Brexit was one of a handful of questions put to the new commission president designate. Von der Leyen, a close ally of the German chancellor, Angela Merkel, told MEPs the Irish backstop was a necessary part of the agreement with the UK.

She faced more questions from central and eastern European MEPs, who complained they had been excluded from the EU package deal on top jobs which had awarded positions to nationals from Germany, France, Italy, Spain and Belgium.

Von der Leyen will be relying on the votes of the European People’s party to make up her majority when MEPs vote on her appointment later in July.

The 60-year-old former gynaecologist, who studied at the London School of Economics, would be the first woman to lead the EU executive in its 62-year history.

While she has won plaudits for her wide-ranging experience, her appointment has been heavily criticised by Socialist and Green MEPs.

The election of the Socialists’ candidate, the Italian MEP David-Maria Sassoli, as European parliament president for a two-and-a-half-year term, came as a consolation. He won a narrow majority, prevailing over a Czech Eurosceptic, the Greens and the radical left, after two rounds of voting.

In his victory speech, Sassoli paid tribute to British MEPs and described Brexit as “painful”. He said: “With all due respect for the choices made by British citizens, this is a political transition that has to be pursued in a reasonable way in a spirit of dialogue.”

Despite this gain for the left, Socialist members of the European parliament were still smarting that EU leaders had rejected their candidate, Frans Timmermans, the first vice-president of the European commission.

His appointment had been fiercely opposed by Poland and Hungary, two governments that are embroiled in a dispute with the EU over violations of the rule of law. Timmermans has been leading talks with Warsaw and Budapest on behalf of the EU, a difficult job that has made him the target of hostile coverage in the state-dominated media in those countries.

Hungarian government spokesman Zoltán Kovács said the “Visegrád Four”, which also includes Slovakia and the Czech Republic, had demonstrated their growing strength and influence over the direction of the EU, in part, because they had “toppled Timmermans”.

Kovács also boasted of the defeat of Manfred Weber, the centre-right candidate to become European commission president, who was the first choice of the German chancellor.

Socialist MEPs meeting in Strasbourg on Tuesday reacted with fury when reports emerged of the Von der Leyen compromise, largely because of the defeat for their candidate who has been the EU flag-bearer for the rule of law.

“It is unacceptable that populist governments represented in the council rule out the best candidate only because he has stood up for the rule of law and for our shared European values,” said the Socialist MEP leader, Iratxe García.

Socialists and Greens were also unhappy that EU leaders had ignored the Spitzenkandidaten process favoured by the parliament, where candidates declared themselves before the European elections.

Q&A What is the Spitzenkandidaten process? Show The Spitzenkandidaten process is a method by which the European Parliament seeks to influence who is appointed as President of the European Commission - a role held from 2014 to 2019 by Jean-Claude Juncker. Under the process, each political grouping in the European Parliament proposes one 'lead candidate' to take the role. The presidency subsequently goes to the political party winning the most seats, or the one that brings together the widest coalition of support for their candidate. However, this is not a formal process set out in any treaty or constitution. The candidate for the role is nominated by the European Council, made up of the leaders of the EU member states. They are able to ignore the Spitzenkandidaten nomination and to chose someone else. The appointment has to be subsequently ratified by the European Parliament though, and therefore choosing an alternative candidate risks provoking conflict between the institutions.

The Von der Leyen appointment “has generated a lot of unhappiness”, one source said, citing “fury” over failure to give Timmermans a big job, but also the German minister’s “chequered” history.

“The other fury is that Ursula von der Leyen is already a compromised defence minister in Germany because of her defence contracts,” the source said. In 2018, the German Bundestag launched an investigation into suspected nepotism and errors by Von der Leyen in the awarding of contracts. The minister admitted last year her department had made mistakes in allocating contracts worth millions of euros to external consultants.

The defence ministry has long been known as the “ejector seat” in German politics and Von der Leyen has generated negative reviews from army chiefs.

Her appointment was part of a package that included proposing Christine Lagarde for the European Central Bank. The Belgian prime minister, Charles Michel, will take over from Donald Tusk as president of the European council. The Spanish foreign minister, Josep Borrell, will be the EU’s foreign policy chief.

The Dutch Green MEP Bas Eickhout tweeted that the “very disappointing deal” was old Europe at its worst. “A backdoor deal with candidates emerging to please the national leaders from Germany, France and Spain. This is not the change that was promised to European voters,” he said.

In an olive branch to MEPs, Von der Leyen said she “truly believes” in the Spitzenkandidaten system and heaped praise on Weber, the defeated candidate.