Services like Netflix, Amazon Prime and Disney+ could face tighter regulation in the UK under government proposals.
Traditional broadcasters like the BBC and ITV have to comply with regulator Ofcom's code covering issues like harm, offence, accuracy and impartiality. But most streaming platforms do not.
The government has announced a review into whether to strengthen the rules.
Meanwhile, ministers have also confirmed a consultation into whether to privatise Channel 4.
The broadcaster is currently funded by adverts but is publicly-owned.
'Potentially harmful'
The only streaming platform that must currently adhere to Ofcom's broadcasting code is the BBC iPlayer. The regulator can issue fines and suspend licences if the rules are broken.
Separate rules regulating incitement to hatred and other "harmful material" apply to streaming services with head and editorial offices in the UK - which include Amazon Prime and Disney+, but not Netflix.
Currently, the Ofcom website contains a statement explaining that "Netflix is based in the Netherlands and therefore not within Ofcom's jurisdiction".
However, some services have introduced their own voluntary procedures - such as Netflix's age ratings partnership with the British Board of Film Classification (BBFC).
In Wednesday's announcement, the government said there was currently an "inconsistent, ad-hoc and potentially harmful gap in regulation".
Culture Secretary Oliver Dowden said the proposed regulation would prevent traditional broadcasters like the BBC from having to "compete with one hand behind their backs".
Writing in The Times, Mr Dowden said UK broadcasters were "holding their own", but added: "Our broadcasters can't do it alone and they certainly can't compete in a digital world while operating under analogue rules.
"This summer we will consult on whether it's time to set the same basic rules for video-on-demand services as we do for traditional broadcasters." He added that the government hoped to "level the playing field".
Last year, Netflix faced criticism from Mr Dowden over scenes in its hit drama series The Crown which contained historical inaccuracies.
According to Ofcom's latest figures, viewers watched subscription streaming services for one hour 11 minutes per day in April 2020 - double the previous year.
In 2019, two in five viewers of streaming services told the Ofcom they could imagine watching no broadcast TV at all in five years' time.
Netflix, Amazon Prime and Disney+ have not commented on the government review, but a Netflix source said the company supported the intentions behind it.
'Public service before profit'
Changes to streaming regulation and Channel 4's ownership could both be included in a new media law that is expected to be unveiled in a white paper this autumn.
On Tuesday, Channel 4 executives warned that privatisation could make it less likely to make shows that are not commercially appealing, whereas the current priority for its programmes is "not about the bottom line".
Chief executive Alex Mahon told a committee of MPs: "We are always, in all the decisions we make, able to put public service before profit.
"When you run commercial businesses, by necessity, your priorities change. They have to. And therefore you have to make decisions differently. You have to think about shareholder returns."
Sir David Attenborough is among those backing a campaign calling for "an open and transparent debate" on the future of public service broadcasting.
The 95-year-old is a supporter of the British Broadcasting Challenge campaign, which last month called on the government "to stop short-sighted political and financial attacks" on broadcasters.
'Strengthened role'
Culture minister John Whittingdale, who previously rejected privatisation in 1996, told BBC Radio 4's Today programme the government "want to make sure Channel 4 had a long-term successful future".
"For that reason we think it's appropriate to look at the ownership model and see whether or not it wouldn't thrive better if it was able to access the kinds of investment capital which the others are able to put into high quality TV content," he said.
Mr Whittingdale compared the network with Channel 5, which he said had enjoyed a higher audience share after it was bought by Viacom in 2014, with more money invested in programming.
"That is one of the benefits of having a financially secure owner," he said. "Now, I'm not saying that is necessarily the best way forward [for Channel 4], but it is certainly something which we think the time is right to consider, in order to make sure that Channel 4 does have a secure future."
In Wednesday's announcement, the government also confirmed it would go ahead with new laws to ensure UK public service broadcasters have a prominent spot on smart TVs and other platforms and devices.