Uniform cigarette packaging slammed as "plain crazy" comes into effect today after the High Court ruled against a legal challenge from big tobacco firms.
Opponents fear the "Soviet style" plain packaging will put tobacco brands at risk of being "eradicated" and lead to a rise in cigarette counterfeiting.
All cigarette packets manufactured from today will share the same green base colour, as well as the same font, size, case and alignment of text.
The policy was promoted by senior Conservatives towards the end of the coalition's term in government last year – and continued after Prime Minister David Cameron returned to Downing Street with a majority.
Meanwhile, health warnings will need to cover 65 per cent of the front and back of packets, to comply with the EU Tobacco Products Directive that is also being introduced today.
"Plain packaging is plain crazy," Chris Snowdon, head of Lifestyle Economics at the Institute of Economic Affairs, said. "It failed in Australia and it will fail in Britain. The fact that a Conservative government supports Soviet style packaging demonstrates that there is nothing the anti-smoking fanatics can come up with that is too ludicrous to be taken seriously by virtue-signalling politicians."
The legal challenge was led by Philip Morris International (PMI) and British American Tobacco (BAT), while Japan Tobacco International (JTI) and Imperial Brands were registered as "interested parties". The challenge focused on the deprivation of intellectual property rights, moves against trademark regulations and unjustified restriction on free movement of goods.
JTI and BAT both confirmed yesterday evening that they will appeal the High Court decision while PMI will not.
"We will continue to challenge the legality of plain packaging," Daniel Sciama, UK managing director at JTI, said. "The fact remains that our branding has been eradicated and we maintain that this is unlawful."
The Tobacco Manufacturers' Association (TMA) said: "Over the years we have campaigned against this ill-advised policy as it will have none of the benefits that the health campaigners have claimed.
"Indeed, it is becoming increasingly apparent that this policy is not delivering on any of its objectives in Australia, where it was introduced in 2012."
Since that date, illicit trade has increased in Australia according to Imperial Brands.
There will be a one-year leniency period in place until 20 May 2017 for UK retailers to sell excess stock. After that date, all current packaging will be banned from sale.
Under the European Union's Tobacco Products Directive implemented today, manufacturers will be banned from producing cigarettes packets with fewer than 20 cigarettes apiece, menthol will be phased out by 2020 and an aggressive new crackdown on e-cigarette advertising will be implemented.