Gunther Oettinger at the European Commission in Brussels | Emmanuel Dunand/AFP via Getty Images Brits can stay in Commission if no conflict of interest, says Oettinger But UK citizens could no longer be EU ambassadors or work in the trade department.

Brits working in the European Commission can remain on the payroll after Brexit but could be moved to lesser roles to avoid conflicts of interest, according to Günther Oettinger, the European commissioner for the budget and human resources.

Speaking to reporters in Brussels Tuesday, Oettinger tried to reassure the more than 1,000 British staffers in the Commission he will not ask for their resignations after March 2019, but warned that they may not be able to stay in their current roles. This would include permanent staff as well as those on shorter contracts.

Among those affected would be Brits working in the Commission's trade department, which will be locked in negotiations with London. British officials could also be removed as heads of the EU's 140 delegations around the world as, Oettinger said, such positions should be filled by "citizens of [the EU27] not from a third country."

The Commission has already decided to remove British staffers from sensitive Brexit-related roles in its department in charge of financial services.

Oettinger did, however, confirm that British officials could remain in management roles such as director-general and deputy director-general.

He also confirmed the Commission was in contact with the Belgian interior ministry about securing permanent residency in Belgium for British officials who are staying with the EU. British officials were often not required to register with the Belgians.

If Brits decide to change their nationality to that of another EU country, Oettinger said such a "highly personal decision" was "up to them."