LONDON – Four major tobacco companies have started a legal challenge in the High Court to the United Kingdom’s new plain packaging rules for tobacco products, BBC News reports. The regulations go into effect in May 2016.

British American Tobacco, Imperial Tobacco, Japan Tobacco and Philip Morris International object to the regulations, which ban the use of logos or brands on any tobacco product, on the grounds that they infringe on their trademarks. The U.K. government’s stance is that the measure will curb smoking.

The new standardized packaging rules will require large health warnings with a dark green or brown cover any other exposed packaging. Brand names will be in small, nondescript letters. The companies claim such a change will ensure all tobacco products look alike, thus eliminating their property rights.

The tobacco firms introduced data from Australia that shows plain packaging—which was introduced there in 2012—has not lowered smoking rates. These rules would “substantially interfere with the claimants’ fundamental rights and freedoms,” said Philip Morris International’s QC, Marie Demetriou.

On the government side, the Department of Health’s QC, James Eadie, wrote in his brief that the move toward plain packaging would lower the appeal of smoking and thus reduce smoking levels.