It was the fifth time the state of emergency has been renewed, meaning the restrictions will remain in force until June 6th in a measure passed by 177 votes in favour, 162 against and 11 abstentions.
The measure has allowed the government to impose a strict lockdown on Spain's nearly 47 million population, significantly limiting the freedom of movement to fight the epidemic which has now claimed 27,888 lives.
But the government's management of the crisis has drawn a barrage of criticism from righwing parties who have denounced its “brutal confinement”, while several hundred protesters have hit the streets demanding “freedom” and Sanchez's resignation.
“It's the Spanish people who have stopped the virus together… nobody has the right to squander what we've achieved during these long weeks of confinement,” Sanchez told lawmakers.
The street protests have been backed by the far-right Vox and the main rightwing opposition People's Party (PP), whose leader Pablo Casado didn't mince his words in the pre-vote debate.
“You are the epitome of chaos and the worst thing is that you are unable to protect the Spanish people without resorting to this brutal confinement,” he said.
But the government says the March 14th state of emergency has allowed it to battle the epidemic and dramatically reduce the daily death toll which by Wednesday had fallen to 95 — a far cry from the 950 registered on April 2nd.
But Sanchez said the fight wasn't over and that extending the restrictions was “the only possible way to effectively fight the virus”, saying there were still “hundreds of new cases every day”.
From Thursday, it will be obligatory to wear masks in public where social distancing is not possible, officials said on Wednesday.
Already compulsory on public transport, the new decree applies to everyone aged six and over.
As the severity of the epidemic has eased, Spain has begun a cautious, staged rollback of the lockdown which is due to finish by late June.
Despite the anti-government protests, a survey published on Tuesday by the state-run Centre for Sociological Studies suggested 95 percent of Spaniards supported the lockdown and 60 percent believed it should be extended.