Internet trolls will face up to two years in jail under new laws proposed by Justice Secretary Chris Grayling.
The previous maximum term of six months will be quadrupled under the plan to tackle the "cowards" who post abusive comments online.
Mr Grayling said the plan was a signal of his determination to "take a stand against a baying cyber-mob".
The move comes just days after the threats directed at Chloe Madeley after she stepped in to defend her mother Judy Finnigan's controversial comments about footballer and convicted rapist Ched Evans.
The Justice Secretary told the Mail on Sunday: "These internet trolls are cowards who are poisoning our national life.
"No-one would permit such venom in person, so there should be no place for it on social media.
"That is why we are determined to quadruple the current six-month sentence."
Ms Madeley, a fitness instructor, was threatened with rape after intervening in the row over her mother's comments about Evans.
Finnigan had inflamed the debate about whether Evans should resume his footballing career by saying his crime was "non-violent" and did not cause "bodily harm" during a panel discussion on ITV's Loose Women.
Mr Grayling said: "As the terrible case of Chloe Madeley showed last week, people are being abused online in the most crude and degrading fashion.
"This is a law to combat cruelty - and marks our determination to take a stand against a baying cyber-mob.
"We must send out a clear message: if you troll you risk being behind bars for two years."
Under the current law, people who subject their victims to sexually offensive, verbally abusive or threatening material on the internet can only be prosecuted in magistrates' courts under the Malicious Communications Act, which carries a maximum prison sentence of six months.
But the new measures will allow magistrates to pass on serious cases to the crown courts, where offenders would face a maximum of two years behind bars.
The change will be made as an amendment to the Criminal Justice and Courts Bill currently going through Parliament.
They measures would also give the police more time to collect enough evidence to enable successful prosecutions to be brought.
Ms Madeley told the Mail on Sunday it was right for Mr Grayling to update the 10-year-old law.
"The current law obviously needs to be reviewed," she said. "It needs to be accepted that physical threats should not fall under the 'freedom of speech' umbrella. It should be seen as online terrorism and it should be illegal."