Ursula von der Leyen and Manfred Weber arrive for a meeting during the first plenary session. | Frederick Florin/AFP via Getty Images Theresa May congratulates ‘first woman’ Commission president nominee UK prime minister says having ‘constructive relationships with those who are appointed’ to EU top jobs in the UK’s ‘national interest.’

LONDON — Theresa May congratulated Ursula von der Leyen, the nominee to become the new European Commission president, on becoming the first woman to take the job — pending European Parliament approval.

The outgoing U.K prime minister said she and her government played a "constructive" role in the tortuous discussions that concluded with the nomination of von der Leyen as part of a package of nominees for the European Union's top jobs.

“This was a package supported by the U.K. and it is in our national interest to have constructive relationships with those who are appointed,” May told MPs in the House of Commons Wednesday. But she said that working with the new appointees after the U.K. leaves the EU would be a matter for her successor; currently most likely to be Boris Johnson, a Brexiteer who has vowed to take the U.K. out of the bloc with or without a deal on October 31.

In response, opposition Labour leader Jeremy Corbyn challenged the prime minister to give her backing to Labour's policy of putting any deal agreed with the EU to the British public in another referendum. May, who has long opposed a second vote, declined.

Last year, von der Leyen said in an interview with Berliner Morgenpost that "we all lose" from Brexit.

“As much as I would like to see the Brits stay in the EU, they voted to leave,” she said. The defense minister advocated working toward an orderly Brexit while preparing for the possibility of a no-deal outcome, saying: “After all, what’s at stake are the foundations of our future relations with our neighbor Great Britain.”