The authorities has written to Sainsbury's and Morrisons asking them to extremity "advertising and promoting" heated baccy products, which it says is against nan law.
The BBC reported successful February nan supermarkets were displaying posters and video screens showing devices which create a nicotine-containing vapour by heating baccy pinch an electrical current.
At nan time, some supermarkets said they believed nan adverts were legal.
In consequence to nan letter, Sainsbury's said it was successful "close interaction pinch nan government", while Morrisons said it would reply "in owed course".
In 2002, nan Labour authorities nether Tony Blair passed a rule banning baccy advertising. It defined a baccy merchandise arsenic thing designed to beryllium "smoked, sniffed, sucked aliases chewed".
Morrisons has based on that this intends that it doesn't use to heated baccy products, arsenic they don't nutrient smoke.
Advertising for Philip Morris International's (PMI) iQos heated baccy instrumentality connected posters and video screens was still connected show successful Sainsbury's and Morrisons stores visited by nan BBC successful June, wherever they were visible to children.
PMI said it believes nan Department of Health's mentation of nan rule is wrong, and said it has "complied pinch each applicable laws and regulations" since it launched iQos successful 2016.
The authorities has now written to nan supermarkets clarifying that successful its opinion, nan rule does use to these products.
A Department of Health and Social Care (DHSC) spokesperson told nan BBC: "In May, we wrote to supermarkets reiterating that nan Tobacco Advertising and Promotion Act 2002… applies to each baccy products presently connected nan market, and formally requested they extremity advertizing and promoting heated baccy products successful stores.
"All baccy products are harmful to health," nan spokesperson added.
Surveys by nan kindness Action connected Smoking and Health propose that consciousness of heated baccy products has risen sharply complete nan past year, and is moreover higher among young adults, compared pinch those complete 40.
Among 11 to 17-year-olds, astir a 4th had heard of heated tobacco, up from 7.1% successful 2022, nan past clip they were surveyed.
Some 3.3% of respondents to their study said they had tried heated tobacco, and for 11 to 17-year-olds, nan fig was 2.7%. While low, nan kindness said this was still "worryingly akin to nan levels of usage among adults".
Experts opportunity that though investigation connected nan wellness effects of heated baccy is limited, it is apt to beryllium little harmful than cigarettes, but worse for you than vapes, and little effective astatine helping smokers quit.
- Are heated baccy products a caller wellness risk?
A spokesperson for Morrisons said it was reviewing nan missive and would respond "in owed course".
Sainsbury's said it believed its ads were compliant pinch nan law. A spokesperson said: "We stay successful adjacent interaction pinch nan authorities and manufacture partners and are readying our modulation to guarantee we besides comply pinch planned incoming legislation."
It would beryllium for a tribunal to norm definitively whether nan authorities is correct that heated baccy advertizing is banned nether existent rule - but truthful acold no-one has brought a case.
The rule will beryllium clarified erstwhile nan authorities passes nan Tobacco and Vapes Bill, which is expected to conclusively prohibition each baccy and vape advertizing and sponsorship.
The measure is making its measurement done parliament and is presently astatine nan committee shape successful nan House of Lords.
Hazel Cheeseman, nan main executive of Action connected Smoking and Health, urged nan authorities to walk nan rule arsenic quickly arsenic possible.
"It is outrageous that definite supermarkets still do not look to beryllium prepared to comply pinch nan law, moreover erstwhile told they are successful breach.
"The longer this takes to resolve, nan much children will beryllium exposed to baccy merchandise marketing," she added.
The Tobacco Advertising and Promotion Act applies UK-wide, but wellness is simply a devolved issue. The devolved administrations successful Northern Ireland, Wales and Scotland each said they agreed pinch nan DHSC successful England that advertizing heated baccy is banned.
Asda and Tesco some said they do not judge baccy advertising.