The EU Commission President, Jean-Claude Juncker, has urged Belgium to grant citizenship to British EU Staff worried about their post-Brexit status.
Mr Juncker called Belgium a kind host and asked its prime minister, Charles Michel, to "show the same generosity when it comes to granting Belgian citizenship" to British EU staff.
When the UK leaves the EU next March Britons will lose their EU citizenship.
The UK and EU have already pledged to protect citizens' rights after Brexit, but that does not mean granting nationality.
Article 49 of the EU staff rules states that "an official may be required to resign" if he or she loses their EU citizenship and is no longer a national of an EU member state.
Many British EU staff are longstanding residents with families.
An internal EU Commission document quoted by Politico news last month said Article 49 would not mean British staff losing their EU jobs, apart from cases involving "conflicts of interest or international obligations".