Britain will be relying on tech giants to police harmful online content until new legislation is introduced post-Brexit, a former home secretary has warned.

Lord Blunkett said a “major gap” will exist in the weeks and months after the UK leaves the EU over who can exert control on video sharing platforms (VSPs) and on-demand services, such as Facebook, Netflix and TikTok.

This will leave the country “at the mercy” of the tech companies to prevent child abuse and terror content appearing on their platforms until further measures are introduced in UK law via the online harms bill, the Labour peer added.

Lord Blunkett’s remarks came as peers approved regulations to maintain Ofcom’s remit to regulate VSPs within the UK jurisdiction once the Brexit transition period ends on December 31.

But peers heard the power will reside with regulators in Europe to deal with platforms based in the remaining 27 member states, with Labour warning the UK will be “shut out” and lacking influence.

The Government has also expressed concerns about a lack of regulation for providers with no physical presence in the UK or European Economic Area (EEA).

It adds a second concern is TikTok, which is established in China with multiple subsidiaries across the EU, there “may be a period of time before its European regulator is decided upon definitively – in the meantime there will be a gap in regulation”.

Speaking during the debate, Lord Blunkett said: “What we have in this order is a recognition that without the online harms legislation promised by the former prime minister Theresa May, we have not just a gap in terms of the maintenance of what Ofcom may or may not be able to do to this date, but a major gap in terms of any control over these video sharing platforms.

“We’re talking about Netflix, Facebook and TikTok, and tick tock it is because the time is passing but the fingers have fallen off the face of the clock.

“So between now and some point the online harms legislation comes in, we’re at the mercy of these big international tech companies.

“And we’re at their mercy in terms of avoidance of child abuse and the dangers that go with that, we’re at their behest in terms of their cooperation on ensuring that these platforms are not used for terrorism purposes, we’re at their behest in terms of whether they agree to continue complying with regulation.

“A very simple question to the minister is I’d like her to spell out to the House just which of these platforms have a prime platform place in the United Kingdom?”

Lord Blunkett voiced concerns that the UK’s powers to intervene and take action could be limited in this period before new legislation is introduced.

Conservative former minister Lord Moynihan said: “It’s really important the minister, and I hope the Government, provide us with absolute confirmation that legislation will not be some time early in 2021 but as early as possible for all the reasons made by Lord Blunkett.”

Liberal Democrat Lord Foster of Bath cited explanatory notes for the regulations as he said: “Online harms legislation will enable us to also deal with the obvious problem of the UK’s inability post-December 31 to have some say on the regulation on the numerous VSPs – such as YouTube and Facebook – which are heavily used in the UK but are regulated in one of the other remaining 27 EU countries.”

For Labour, culture spokesman Lord Bassam of Brighton said: “Can we be assured this regulatory gap will be closed pronto?

“We need the online harms legislation to provide the certainty we all crave.”

For the Government, Culture minister Baroness Barran said draft online harms legislation to protect internet users is expected to be “ready in early 2021”, with responses to a consultation published this year.

She also outlined how “informal cooperation” will exist with the EU to ensure regulation of VSPs in their jurisdiction helps protect the UK.

On how many VSPs would be regulated by Ofcom, Lady Barran said: “My understanding is Ofcom currently anticipates only a small number of services will fall within the UK’s jurisdiction.

“We expect this to include platforms such as Vimeo and Twitch, but it is Ofcom’s role to determine which platforms are in scope and they will be able to do this once they’ve engaged fully with platforms and concluded their consultations on guidance and scope.

“Platforms providing services which fall within the UK jurisdictions will be required to notify Ofcom of provision of these services from April 2021.”