The director of the Centre for Health Alerts and Emergencies believes masks are no longer necessary "in almost all scenarios".
There will be a meeting on Thursday at which mask-wearing will be discussed.
The Spanish government's decree in December was more a political than a necessary measure to show there was concern about infections.
Obligatory wearing of masks outdoors - a "strictly temporary" measure.
Five regions have scrapped restrictions and done away with the Covid passport.
In the Madrid region, they are "not particularly worried".
Only one regional health minister has asked for a reduction to be considered.
A four-week minimum period criticised as an "immunological absurdity".
Spain's Health Ministry reported a new record in the national 14-day COVID-19 infection rate.
Congress is due to debate the mask-wearing decree.
Certain regions have already gone much further, e.g. Catalonia has reintroduced a curfew.