A ban on tobacco advertising in newspapers, magazines and on billboards comes into force in Britain today.
The ban, which is part of a government drive to try to reduce smoking-related deaths, was welcomed by anti-tobacco campaigners who said it was "a great moment for public health".
Mr Clive Bates, director of anti-smoking group ASH, said: "It will save tens of thousands of lives as the attractiveness of cigarettes begins to decline and the tobacco industry struggles to recruit new smokers to replace the customers that are dying off".
Dame Helena Shovelton, chief executive of the British Lung Foundation, said: "We wouldn't dream of advertising heroin or cocaine yet tobacco is more addictive.
"For over 50 years we've known about the links between smoking and lung cancer and now at last we will see an end to the promotion of the UK's biggest cancer killer".
The British Medical Association (BMA) also welcomed the ban, but urged the government to now go on and prohibit smoking in public places.
However Mr Simon Clark, director of the smokers' pressure group FOREST, said the ban was a pointless political gesture that would have very little effect.
"The idea that people start smoking because of advertising, or are unaware of the health risks, is nonsense," he said.
New legislation banning the advertising and promotion of tobacco products in Ireland has been stalled due to the failure to notify aspects of it under an EU directive. However, it seems certain that the legislation will be re-enacted in a revised form later in the year.