Spain's conservative party called Sunday for the resignation of Prime Minister Pedro Sanchez, saying it would file a legal complaint against his Socialist party after new corruption allegations against an associate.

The demand follows media reports of a police inquiry that put Sanchez's longtime confidant and former minister Jose Luis Abalos at the heart of a corruption scandal over the purchase of face masks during the Covid-19 pandemic.

"We are asking Pedro Sanchez to resign, he cannot stay a minute longer at the helm of Spain's government," the right-wing Popular Party's (PP) secretary general Cuca Gamarra said at a press conference.

"The details that are being revealed" show "systemic corruption spearheaded by Pedro Sanchez", Gamarra said. 

On Monday, "the Popular Party will press charges against the Socialist Party over suspicions of illegal financing, corruption and influence-peddling, so that an investigation into this unprecedented scandal can be carried out through to the end," she said.

Abalos, a close ally of Sanchez's for years, was ousted from the Socialist Party after he refused to resign when the corruption allegations came out in February.

He has not yet been charged with any wrongdoing.

Gamarra also noted the accusations against Sanchez's wife Begona Gomez, who is alleged to have used her husband's position as leverage within her professional circles while teaching a masters program at a Madrid university.