By David Ljunggren

Canada unveiled some of the world's largest and most graphic anti-smoking labels on Tuesday on the grounds that smokers were starting to ignore existing warnings on cigarette packs.

The new labels have to cover 75 per cent of the front and back of each pack of cigarettes and small cigars, and will be mandatory by the middle of next year. Existing anti-smoking labels cover 50 per cent of a pack.

The 16 labels include pictures of a woman dying of lung cancer in a hospital bed, a man with a hole in this throat after surgery for smoking-related larynx cancer, and a close-up shot of a diseased and cancerous tongue.

"We want to make the images larger and more noticeable and more understandable ... The images are pretty gross. They can be a little bit scary as well, but that is the reality of smoking," said federal Health Minister Leona Aglukkaq.

"Over time, people get used to seeing the old pictures so we want to grab people's attention once again," she said at an event to unveil the images.

The new labels can be seen here#cigarettes

Tobacco manufacturers and importers will have until March 21 2012 to switch over to the new labels and retailers must only carry packs with the bigger warnings by June 19.

"It's fantastic ... the evidence is that the larger the size (of the label), the larger the impact," said Rob Cunningham, a policy analyst at the Canadian Cancer Society.

Only Uruguay, which requires warning labels to cover 80 per cent of a package, has tougher regulations, he said.

The adult smoking rate in Canada fell to a record low 17 per cent in 2010 from 24 per cent in 2000, a year before the first warning labels started to appear.

The Canadian Public Health Association welcomed the move, while noting that smoking was "the single most preventable cause of disease, disability and premature death in Canada."

In the United States, several large tobacco companies are suing the federal Food and Drug Administration for requiring more graphic health warnings on packages no later than September 2012. The labels variously include pictures of bodies, diseased lungs and rotting teeth.

Major producers of tobacco sold in Canada include R.J. Reynolds Tobacco Co, Japan Tobacco's JTI-Macdonald unit, Rothmans Benson & Hedges Inc, which is partly owned by Philip Morris and Imperial Tobacco Canada Ltd, a unit of British American Tobacco.

Imperial Tobacco said the new labels were "poor policy for political gain" and would not cut the number of smokers.

"We ... believe that the health risks have been known for decades and that the existing regulations, including the 50 per cent health warning, provide sufficient information to consumers in order for them to make an informed decision," said company spokesman Eric Gagnon.