Tensions after more than two months of lockdown in Italy have boiled over into sexist attacks and threats against Education Minister Lucia Azzolina, who now has police protection.
Right-wing Senator Giuseppe Moles of Forza Italia spoke out publicly, warning the minister that credibility was like virginity and "easy to lose".
Furious senators in her Five Star party demanded that Mr Moles apologise.
A deputy health minister and a regional governor also have police guards now.
The deputy minister, Pierpaolo Sileri, had received threats linked to coronavirus aid. Like Ms Azzolina, he is in the anti-establishment Five Star movement, part of Italy's coalition government.
Attilio Fontana, governor of the Lombardy region - epicentre of Italy's coronavirus crisis - was also assigned police protection after being threatened on social media. Graffiti in Milan labelled him a "murderer".
He is in Matteo Salvini's anti-immigration League, and his Lombardy government has been heavily criticised for shortcomings in its crisis response, such as shortages of some medical kit in the severely stretched health service.
Austria's Justice Minister Alma Zadic, a Green politician, was reported to be under police protection in January after being targeted by far-right threats on social media.
During question time in the Senate on Thursday Senator Moles unleashed a tirade against Ms Azzolina, 37, who is battling to address widespread frustration over the paralysis in education caused by the coronavirus crisis.
"We've heard so much: school closing yes, school closing no; in April all students will be promoted, in May some students will fail; in September lessons can be half at school, half at home," he said.
"I remind you minister that school requires credibility and seriousness. And credibility is like virginity: easy to lose, difficult to maintain, and impossible to recover."
Ms Azzolina did not hit back at the senator - her social media posts have focused on her plans to get Italy's students back into class, while ensuring that protection against coronavirus is in place. Unlike some other countries, Italy is delaying the reopening of schools until September.
Colleagues sprang to the minister's defence. Five Star Senator Barbara Floridia called on Mr Moles to apologise. His comment comparing credibility to virginity was even more serious, she said, because it had been made "in front of a woman, a minister, who has in recent days suffered every kind of attack and insult" which meant she needed police protection.
A decree for schools has been adopted by the Senate - the upper house of parliament - including a host of new hygiene rules drafted by a scientific expert panel.
There will be a one-metre social distancing rule in classrooms, compulsory masks for those aged over six and staggering of school timetables to keep student numbers down. Anyone with a temperature of 37.5C will have to stay at home.
Among those who attacked Ms Azzolina on social media was Vittorio De Prà, a maths teacher at a secondary school in Ovada, a small town in Piedmont, northern Italy. He now faces possible suspension for sexist abuse, the daily La Stampa reports.
He apologised, saying: "shut up at home for some time, exasperated by this situation, I let myself go and wrote what everyone has read and rightly condemned.
"I was anxious because nothing was known about the state exams for high school and there was talk of teachers having to be present for the tests. I also have health problems. So I did a stupid thing. I can only apologise to the minister."
Senator Moles also apologised, insisting that he was referring to the credibility of school and he was not being sexist.