Someone was arrested by police for making a death threat against Normanton, Pontefract and Castleford MP Yvette Cooper, according to her husband, ex-cabinet minister Ed Balls.
Former education secretary Mr Balls said his wife was "scared" after having to step up the level of security around her, following threats during the current tense political climate.
The retired politician-turned-reality-television-star made the admission when asked about the couple's daughter Ellie, whose passionate plea for MPs - including the Prime Minister - to tone down their language went viral on Twitter last week.
He told ITV's This Morning: "It's a very funny thing. We've spent all of our political lives making sure that our children are not in the news. Ellie's now 20 and she just decided that she wanted to say something.
"Like lots of MPs, Yvette has had lots of threats and lots of people arrested for... there was someone last week for a death threat, and so I think the combination of the children knowing that, and seeing the security, which all MPs have now, alongside language which was so confrontational and angry, she was upset about it."
Ms Cooper, the chairman of the influential home affairs committee, is not the first to have been targeted in recent days.
A 36-year-old man has been charged in connection with a disturbance outside the constituency office of fellow Labour MP Jess Phillips, with a court case due to begin on October 10.
It follows in the wake of terse secenes in the Commons after Boris Johnson was last week accused of dismissing abuse fears of female MPs as "humbug".
The PM has been accused of stoking up a "people versus Parliament" narrative in a bid to increase support for a no-deal Brexit.
Mr Balls, chairman of Norwich City FC and a former Strictly Come Dancing contestant, said it felt as if "things have gotten out of control" in the aftermath of the 2016 referendum.
He said: "I think she's scared too. I think particularly women MPs, Labour and Conservative, have had a lot of these threats.
"And nobody knows if it's on the internet (or) a lone wolf, and then you have these people whose windows are being broken and office attacks, and it just feels as though things have gotten out of control."
He echoed his daughter's words in calling for those on the political frontline to "calm this down".
"It's legitimate for people to have disagreements, we should argue about things, but you don't have to do so in a way which is so, not angry, but venomous," said the former shadow chancellor.
"And I think what Ellie was saying in her article, which as I say rather took us aback, was that politicians have got to calm this down, starting at the top.
"We've got to find a way to bring people together and start treating each other with civility, rather than all this violent language."
Mr Balls said the current atmosphere in Parliament was putting him off considering standing for MP again.
He was one of the prominent members of Ed Miliband's top team to lose their seats at the 2015 general election.
"I don't think I want to be there at the moment, it's pretty awful," said the former Morley and Outwood MP.
"It's not going to happen and, as we're talking about, I'm doing very different things now. And supporting Yvette trying to do the right thing, as all these MPs are trying to do."