Karen Pierce, the Foreign Office (FCO) political director, has been appointed UK ambassador to the United Nations, the first woman to be given the most prestigious post in the British diplomatic service since the UN’s formation in 1945.

Seen as a trailblazer for women in the FCO, she will take over in January, and succeeds 18 different male postwar UK permanent representatives at the UN in New York.

The high-profile UN posting comes at a critical time for the FCO as the UK battles to prove its departure from the European Union will not diminish British influence on the international stage, especially at the UN. Many have questioned the long-term viability of the UK’s continued place as one of the permanent five veto-wielding members of the security council, with some claiming the UK’s status looks anachronistic, especially since France will effectively become the voice of the EU among the group.