Tobacco companies lost a court battle over the warnings

Another warning depicts a drooping cigarette accompanied by a message about tobacco-related impotence.

The visual impact of the images will be helped by their size. The rules from the Canadian Health Department say the warnings will have to cover 50% of the packet.

If smokers are not deterred by the image on the outside and open the packet, they will see more detailed written health information on the inside.

Test case

There are also new, less hard-hitting warnings for cigars, and pipe and chewing tobacco.

The health warning regulations have angered the tobacco companies. They complained about them on a number of grounds, saying the new packets would be too technically difficult to print and would not allow enough room for their trademarks.

They also launched an unsuccessful court challenge against the government's proposals.

The impact of the Canadian initiative is being studied by other public health authorities around the world, including those of the European Union, where more hard-hitting tobacco health warnings are being proposed.