A ban on social media for under-16s has been backed by the House of Lords following growing calls from campaigners including actor Hugh Grant.

In a heavy Government defeat, peers supported the cross-party move by 261 votes to 150, majority 111, and means it will have to be considered by MPs in the Commons.

Supporters of the Australian-style ban have argued parents are in “an impossible position” with regard to the online harms their children are being exposed to.

Technology Secretary Liz Kendall announced a three-month consultation this week, which will consider the advantages and disadvantages of a ban, as well as possible overnight curfews and actions to prevent “doom-scrolling”, before reporting back in the summer.

However, Tory former schools minister Lord Nash, who has spearheaded calls for a ban, argued the late concession simply represented more delay.

He said: “The Government’s consultation is, in my view, unnecessary, misconceived and clearly a last-minute attempt to kick this can down below the road.”

Proposing an amendment to the Children’s Wellbeing and Schools Bill, the Conservative peer told the upper chamber: “Many teenagers are spending long hours – five, six, seven or more a day – on social media.

“The evidence is now overwhelming as to the damage that this is causing.

“We have long passed the point of correlation or causation. There is now so much evidence from across the world that it is clear that by every measure, health, cognitive ability, educational attainment, crime, economic productivity, children are being harmed.”

He added: “This is going to happen. The only question is when. We have the opportunity to do it now in this Bill, and every day which passes, more damage is being done to children. We must act now.”

Paediatrician Baroness Cass said: “The first duty of Government is not to consult, it is to act.”

The independent crossbencher added: “If we think children may be in danger, we act first and we ask questions later.”

Filmmaker and children’s rights campaigner Baroness Kidron said: “A consultation is the playground of the tech lobbyist and inaction is the most powerful tool in politics.”

She added: “The Government has shown it will only act under pressure, not principle.”

Tory peer Baroness Bertin, who led an independent review of pornography published last year, branded the business model of social media firms as “sort-of borderline criminal, but certainly very toxic and it is so sophisticated”.

The former Downing Street press secretary said: “They have already made off like bandits with our children’s innocence.”

Former Playschool presenter and Liberal Democrat peer Baroness Benjamin, who is vice-president of the children’s charity Barnardo’s, said: “Now is the time for us to act decisively because each minute we wait more damage is done to our children’s wellbeing.”

But fellow Liberal Democrat Lord Clement-Jones argued a blanket ban “risks protecting children in a sterile digital environment until their 16th birthday, then suddenly flooding them with harmful content without having developed a digital literacy to cope”.

Urging the need for action, Tory shadow education minister Baroness Barran said: “We don’t need another national conversation. The nation has spoken very clearly about its level of concern, and parents and children will not thank us.

She added: “We owe it to our children to act now and protect their childhood.”

Responding to the debate, education minister Baroness Smith of Malvern said: “We know many in this House and the other place have concerns around children’s online safety, how much screen time they get, and how this can impact wellbeing.

“Rest assured, Government hears those concerns, and we are prepared to act to deal with them.”

She added: “It is clear that there are, there is a range of different views on the action that we need to take, even as there is a consensus that action is needed.”

In a bid to reassure peers, the minister promised to bring forward a future amendment enabling the secretary of state to enact the outcome of the “short, sharp” consultation.

She said: “The question is not whether the Government will take further action. We will act robustly. The question is how to do this most effectively.”

Speaking after the vote, Lord Nash said: “Tonight, peers put our children’s future first.

“This vote begins the process of stopping the catastrophic harm that social media is inflicting on a generation.”

Online safety campaigner Ellen Roome, who believes her 14-year-old son Jools died while attempting an online challenge, told the Press Association she was “really delighted” with the vote.

She added: “Everybody’s campaigned really hard for it.”

Hollywood star Hugh Grant was one of the signatories in a letter to Sir Keir, Conservative leader Kemi Badenoch and Liberal Democrat leader Sir Ed Davey, backing the amendment.

The letter was also signed by Esther Ghey, whose 16-year-old daughter Brianna was murdered by two teenagers in 2023.

Ms Ghey has previously said her daughter had a “social media addiction” and “desperately wanted to be TikTok famous”, putting her “in constant fear about who Brianna might be speaking to online”.

Other signatories include singer Peter Andre and actor Sophie Winkleman, while the letter is also backed by Parentkind and Mumsnet.

It states: “Children are being served up extreme content without seeking it out. Parents know this has to stop. But they cannot do this alone, and they are asking for politicians to help.”