As of this week, tobacco products will have to be hidden in all UK shops, pubs and clubs, not just supermarkets and other large stores.
While a ban on display was introduced at larger outlets in 2012, smaller retailers were given more time to comply.
The aim of the ban is to discourage younger people from taking up smoking - as many as two thirds of smokers take up the habit before the age of 18.
"The ban on displaying cigarettes and tobacco is the next step to help us limit the attraction of cigarettes, especially among young people, and further raise awareness about the dangers of smoking," commented health minister Mark Drakeford.
"Evidence from Cancer Research UK shows that despite the success of the ban on tobacco advertising, prominent displays remain a key factor in encouraging young people to take up smoking."
On top of the display ban, plans are in place for all tobacco packaging to be standardised.
A poll by researchers from King's College London indicated that retailers were generally happy with the move.
"Retailers showed an interest in reducing their reliance on tobacco sales - we know that they will benefit from consumers purchasing products other than cigarettes, which are deadly and addictive," says professor of tobacco addiction Ann McNeill.
"Other consumer products will have a higher profit margin than cigarettes. We should explore how best to support retailers in diversifying away from tobacco."
However, this poll was very limited - researchers interviewed just 68 retailers - and many are concerned that the new regulations place an unnecessary burden upon them. They've been forced to replace their display units, and will inevitably take longer to serve customers, they say.
Suleman Khonat, a Blackpool shopkeeper and spokesman for the Tobacco Retailers' Alliance, says that there's been no research into whether or not the display ban in larger stores has had any effect.
Similarly, he says, there's no evidence that plain packaging has cut smoking rates in Australia.
"So much for the promise that this Government would only introduce legislation based on hard evidence," he says.
"So much too for its promise to reduce red tape to make it easier for small shops to do business and help boost the economy. This will do neither. It will simply undermine legitimate businesses while helping the tobacco smugglers, who are already thriving."
The Trading Standards Institute will be responsible for inspecting small shops and enforcing the law.
The Association of Convenience Stores has more information on how retailers should comply with the new regulations, here.
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