Rishi Sunak has been forced into a humiliating climbdown by his own MPs over tougher punishments for social media bosses who fail to protect children online.
The Prime Minister caved to Tory pressure on the Online Safety Bill after an amendment to make tech chiefs criminally liable if they do not block minors from seeing damaging content garnered dozens of signatures.
The rebels have now dropped the amendment ahead of today's Commons debate following intense talks with Culture Secretary Michelle Donelan at the weekend.
A source said Ms Donelan backed the aims of the amendment but the wording "wasn't quite right".
It is the third time that the wavering PM has surrendered to Tory revolts since entering No10 in October - abandoning onshore wind farms and housing planning reforms.
Ex-Home Secretary Priti Patel and former Tory leader Sir Iain Duncan Smith are among those backing the change, along with Labour.
Mr Sunak would have faced his first big Commons defeat if he pushed ahead without compromise.
The rebel amendment looks to introduce a new clause into the Online Safety Bill to "make it an offence for the provider of a user-to-service not to comply with the safety duties protecting children" which are set out in the draft law.
In its current form, the new internet safety law would require tech companies to remove illegal material from their platforms, with a particular emphasis on protecting children from seeing harmful content.
Social media platforms and other user-generated, content-based sites that break the rules would face large fines from the sector's new regulator, Ofcom.
But the proposed law would only hold tech bosses liable for failing to give information to the watchdog.
Sir Iain said the draft legislation was "weak" and children needed greater safeguards against seeing "extreme pornography" and material about suicide.
Shadow Culture Secretary Lucy Powell said: “Labour has been calling for stronger criminal sanctions for months, however the enforcement is now over a narrower set of measures after the Government gutted much of the Bill before Christmas.
“We’ve got no idea where the Government truly stand on these issues. They’ve flip flopped, one minute massive weakening the Bill, the next minute forced into a minor strengthening.
“Rishi Sunak is too weak to stand up against vested interest, Labour is on the side of the public.”
Richard Collard, associate head of child safety online policy at the NSPCC, said: "By committing to senior manager liability the Culture Secretary has sent a strong and welcome signal that she will give the Online Safety Bill the teeth needed to drive a culture change within the heart of tech companies that will help protect children from future tragedies.
"The Government has rightly listened to the concerns raised by MPs and we look forward to working with Ministers to ensure the final legislation holds senior managers accountable in practice if their products continue to put children at risk of preventable harm and sexual abuse."
Ian Russell, the father of schoolgirl Molly Russell, who killed herself after viewing harmful material on social media, said the threat of imprisonment is "the only thing" that will make the bosses "put safety near the top of their agenda".
"I think that's a really important thing in terms of changing the corporate culture at these platforms," he told BBC's Newsnight.
