A further delay to legislation aimed at cracking down on harmful content online could “cost vulnerable young lives”, Molly Russell’s father has said.

Ian Russell – the father of Molly, 14, who ended her life after viewing self-harm content online – said the delay “demonstrates the damaging effects of the current political turmoil”.

The Online Safety Bill would update tech sector regulation, with social media and other platforms set to be held accountable for finding and removing harmful content from their sites, with a particular focus on protecting children.

The legislation was put on hold during the Conservative leadership race in the summer for the new Prime Minister to take on.

Last week, Commons Leader Penny Mordaunt told MPs the Bill would return to the House for its remaining stages on November 1.

But on Thursday, when outlining the business for the House for the following week, Ms Mordaunt made no mention of the Bill, including when specifically addressing November 1.

Campaigners have warned that every day the Online Safety Bill is delayed is “another day imagery of children being sexually abused spreads further online”.

Addressing criticism from Labour, Ms Mordaunt said the legislation “remains a priority”, and that the Government needs to “ensure that there is time for members to properly look at amendments”.

But Labour questioned if the Bill had been pulled by the Prime Minister to “appease” the new Trade Secretary Kemi Badenoch, who has previously voiced concerns that the legislation should not “overreach”.

Commenting on the delay, Mr Russell said: “With four school-age children dying by suicide each week in the UK, delaying the Online Safety Bill, for the second time in four months, demonstrates the damaging effects of the current political turmoil.

“Every week’s delay to this vital legislation means harmful online content will remain readily available and, as Molly’s inquest has recently shown, tragically this can cost vulnerable young lives.

“The Online Safety Bill has been five years in the making so far, its public consultation, careful drafting and pre-legislative scrutiny have produced a Bill perfectly fit for the next stage of debate in the House of Lords, where further amendments will no doubt be made.

“It is essential any delay to this Bill is kept to an absolute minimum.

“I hope the assurances I have been given by the Secretary of State that the Bill will be in the Lords by Christmas will prove to be more than just fine words.

“For the sake of our young, who are currently exposed to online dangers on a daily basis, this legislation can’t come soon enough.”

Molly, from Harrow in north-west London, ended her life in November 2017 after viewing suicide and self-harm content online, prompting her family to campaign for better internet safety.

Addressing the delay in the Commons on Thursday, Labour shadow Commons leader Thangam Debbonaire said: “Where is the Online Safety Bill, which was first mooted a decade ago? Now we’ve been waiting four years – has the Prime Minister been forced to pull it to appease his new Trade Secretary?

“Since the Conservatives first announced their intention to regulate, seven other jurisdictions have introduced online safety laws, and in the UK in that time online crime has exploded, child sexual abuse online has become rife, scams have proliferated.

“Every day that goes by without the Bill the suffering continues. We hear it’s been delayed and not pulled. So can I yet again offer Labour’s willingness to work with the Government to get this Bill over the line as soon as possible?”

Ms Mordaunt responded: “The Online Safety Bill will be back in the House shortly. It is a priority for this Government. It remains a priority for this Government.

“We do need to ensure that there is time for members to properly look at amendments. And that was the issue why it was not brought back before. But I will be announcing business in the usual way, and we are committed to that Bill.”

Richard Collard, child safety online policy and regulatory manager at the NSPCC, said: “Families have long paid the price for the failure of tech firms to make their sites safe for children – they should not have to pay twice due to turmoil in Westminster.”

Susie Hargreaves, chief executive of the Internet Watch Foundation, said: “Each day this crucial legislation is delayed is another day imagery of children being sexually abused spreads further online. This is the reality.

“Our hotline analysts see the consequences, and last year they removed more images and videos of children suffering sexual abuse and rape from the internet than ever before.”

She added: “Law enforcement, tech businesses and charities are working hard to keep the internet safe, but they need certainty. Delaying the passage of this Bill would undermine that.”