General Miguel Angel Villarroya's resignation on Saturday came as a scandal brews over Spanish military and political officials getting early vaccinations supposedly reserved for health workers and people in retirement homes.

Socialist Prime Minister Pedro Sanchez's government said it had nominated Admiral General Teadoro Lopez Calderon, a 66-year-old who has spent 47 years in the armed forces, as Villaroya's replacement.

Villaroya's resignation came just a day after the interior ministry sacked a lieutenant-colonel who served as a staff liaison to the civil guard, because an internal report found he had received the shot without being a priority.

The report accuses several other defence staff members of improperly receiving the vaccine, and Robles has warned more resignations could follow.

Politicians have also resigned over receiving the vaccine out of turn, including Manuel Villegas, health advisor for the southeast Murcia region.

Earlier on Tuesday the health advisor to the Spanish north African enclave of Ceuta, Javier Guerrero, became the latest politician to step down, after refusing for days to so, arguing he had not violated any protocol.

"As far as we know...no minister has been vaccinated, and ministers will be immunised when it is their turn," government spokeswoman Maria Jesus Montero said Tuesday when asked if any cabinet member had received the jab.

Spain has been hard-hit by the pandemic, having recorded over 56,000 deaths from nearly 2.6 million cases so far.