Hostility towards the United Nations Sudan envoy Volker Perthes had been building within Sudanese army circles for many months before the country's foreign ministry declared him persona non grata on Thursday night.
According to Sudanese officials aligned with the army, Perthes "advanced the cause" of rival Rapid Support Forces (RSF) commander Mohamed Hamdan Dagalo during negotiations before and after the agreement in December of a framework deal to transition Sudan back to a civilian-led government.
It was the breakdown of the negotiations that followed the December deal - and particularly the question of how and when the RSF would be incorporated into the army - that helped spark the beginning of Sudan's current war, which began on 15 April when paramilitary forces launched an attack on the army's headquarters and the official residence of its commander, Abdel Fattah al-Burhan.
On Thursday night, the anger at Perthes escalated, as the Sudanese foreign ministry released a statement saying it had notified the UN's secretary general, Antonio Guterres, that the German had been declared "persona non grata as of today".
This means the former academic, who has led the UNITAMS mission intended to assist Sudan's transition to civilian government since 2021, has officially been asked to leave the country. Perthes was in Ethiopia when the statement was made and had not been in Sudan for at least a fortnight.