The nominee to replace Jean-Claude Juncker as European Commission president has vowed to defend the “precious” Irish backstop and signalled that she would not reopen Brexit talks.

At a hearing of MEPs in Brussels Ursula von der Leyen took the same line as her predecessor, dashing hopes in Westminster that the EU would use the leadership handover to adjust its stance.

“I think it’s a good deal, but it is your responsibility and your noble task to sort this out,” the German politician told a Remain-backing British MEP in the European parliament.

Responding to another question from an Irish MEP about the controversial backstop policy she said: “I think the backstop is of utmost importance and we absolutely know how crucial this nonexistent border is for you.

“Having the backstop in the Brexit deal is precious, important and has to be defended.”

An immigrant's tale: Leaving Britain to escape Brexit hostility Show all 20 1 /20 An immigrant's tale: Leaving Britain to escape Brexit hostility An immigrant's tale: Leaving Britain to escape Brexit hostility Maria, 31, holds her daughters, Elena, two, and baby Ioana, weeks old, in her London home A few months after Britain voted to leave the European Union, Maria was told her to go back to her native Romania whilst in hospital by an elderly English woman. “You are a foreigner, your place is not here” recalls Maria, who was stunned Reuters An immigrant's tale: Leaving Britain to escape Brexit hostility Maria and her husband Adi, 37, take their daughters for a walk in Hampstead Heath near their home The couple are preparing to leave Britain later this year with their two children, fed up with what Maria says is xenophobia and the rising cost of living in London Reuters An immigrant's tale: Leaving Britain to escape Brexit hostility Elena holds up British passports belonging to her and her sister. Both children have dual citizenship, but their parents do not want to apply for this despite having permanent residency in Britain Reuters An immigrant's tale: Leaving Britain to escape Brexit hostility Maria holds daughter Ioana, who is less than a week old, while Elena wipes a table Maria had never faced direct abuse over her nationality in her 10 years in the country until that moment at the hospital Reuters An immigrant's tale: Leaving Britain to escape Brexit hostility Adi spends time with his daughters Reuters An immigrant's tale: Leaving Britain to escape Brexit hostility Adi plays hide and seek with his daughter Elena Reuters An immigrant's tale: Leaving Britain to escape Brexit hostility Food is served Reuters An immigrant's tale: Leaving Britain to escape Brexit hostility Adi takes his daughter, Elena, to nursery Reuters An immigrant's tale: Leaving Britain to escape Brexit hostility Adi's sister, Nicoleta, 34, carries her niece Elena in a restaurant after a trip out Reuters An immigrant's tale: Leaving Britain to escape Brexit hostility Adi and Maria cook together at their home Reuters An immigrant's tale: Leaving Britain to escape Brexit hostility Adi holds his baby daughter, Ioana Reuters An immigrant's tale: Leaving Britain to escape Brexit hostility Adi and wife Maria take their daughters for a walk in Hampstead Heath Reuters An immigrant's tale: Leaving Britain to escape Brexit hostility Berwyn, a neighbour of the couple, who moved to the UK in the 1980s from Australia, says goodbye to Maria after a visit at her home. Berwyn has dual citizenship - Australian and Irish as she lived in Ireland for a few years before moving to Britain. She calls the family her 'dearest Christian Romanian friends' Reuters An immigrant's tale: Leaving Britain to escape Brexit hostility Religious pictures including a portrait of Arsenie Boca, a Romanian Orthodox monk, theologian and artist (top), hang on the wall at the home of Adi and Maria Reuters An immigrant's tale: Leaving Britain to escape Brexit hostility Maria dries Elena after giving her a bath after nursery Reuters An immigrant's tale: Leaving Britain to escape Brexit hostility Maria holds her baby daughter Ioana Reuters An immigrant's tale: Leaving Britain to escape Brexit hostility Adi works with his colleague Alexandru, who is also from Romania, for a removal company Reuters An immigrant's tale: Leaving Britain to escape Brexit hostility Maria holds her daughter Elena Reuters An immigrant's tale: Leaving Britain to escape Brexit hostility Neighbour, Berwyn, holds baby Ioana Reuters An immigrant's tale: Leaving Britain to escape Brexit hostility Adi and Maria, along with their daughters, leave St Andrews church in Kingsbury after attending a service Reuters

The declaration represents the candidate’s first comments on Brexit since she was selected for the post.

Boris Johnson and Jeremy Hunt have both said they would try to renegotiate the Brexit withdrawal agreement – despite all EU leaders having said the matter is closed for them since last year.

Ms Von der Leyen was nominated by EU leaders to be the political head of the EU’s executive branch for the next five years. She faces a vote in the European parliament to confirm her appointment next Tuesday and is currently in both open and closed consultations with MEPs from across the parliament.

One source familiar with discussions between British MEPs and Ms Von der Leyen said the nominee had privately expressed openness to a further extension of Article 50 later this year. The Brexit negotiating period currently runs out on 31 October; any final decision over an extension would be made by EU leaders at a summit ahead of the deadline.

The centre-right German defence minister’s appointment is not a sure thing: while she is likely to be approved by MEPs, she needs to win support from socialists, liberals, and Eurosceptics in the parliament to be confirmed.

The parliament’s green group, enlarged and emboldened after a good set of results at the European elections in May, have already signalled they would vote against her appointment.