"The Covid-19 pandemic has shown that highly mobile workers who frequently move either within or in and out of the European Union (EU) are irreplaceable during a public health crisis. Nevertheless, they often remain the least protected and most vulnerable.
Measures introduced to protect workers in standard employment relationships during a public health crisis might not reach certain groups of highly mobile workers. As a result, they may become even more marginalised during a crisis.
This is further exacerbated by such workers often being foreigners in their host countries. Both host and home countries fail to protect them adequately, and this can be even more pronounced for workers from third countries, outside of the EU.
During the COVID-19 pandemic, pre-existing EU law has failed to protect highly mobile workers and, so far, the guidance and policy actions taken by the European Commission have failed them too.
To enhance protection for highly mobile workers in the long term, a significant (upwards) convergence of social and labour law standards between countries and for different groups of workers is needed. In the medium term, a pan-European social safety net for crisis situations should be created, with the needs of highly mobile workers in mind. And in the short term, targeted emergency measures including both support and protective standards for this group of workers should be adopted, ideally at the EU level or, if not possible, at the national level.
This policy brief's focus is on ‘highly mobile workers', namely those workers whose place of employment is not a single Member State: they either regularly cross borders due to the nature of their work, work in multiple Member States, or cross a border every day in order to work in a Member State other than the one where they permanently reside (De Wispelaere and Rocca 2020).
The following groups of workers are of interest here:

international transport workers (drivers, seafarers and air crew members);
seasonal workers;
frontier workers, who travel to a country other than their own for work on a regular basis;
and other types of highly mobile workers."

Support: Digital