TORONTO - Several licensed marijuana producers have penned a letter to Ottawa, urging the federal government to allow them to brand their products and provide medical cannabis on a tax-free basis.

The seven producers - Tilray, Tweed, Mettrum, CannTrust, Green Organic Dutchman Holdings, RedeCan Pharm and Delta 9 Bio-Tech - are lobbying the government ahead of the week of April 10, when legislation legalizing recreational use of the drug is expected to be introduced.

A federal task force has recommended requiring plain packaging for cannabis and advertising restrictions similar to those placed on the tobacco industry.

But in their letter, the licensed producers argue that preventing them from branding their products will make it tougher for them to compete with black market operations such as illegal dispensaries.

"Brands allow professional companies to separate themselves from less scrupulous competitors," says Brendan Kennedy, president of B.C.-based marijuana producer Tilray.

Some health advocates have argued that restricting branding and advertising is necessary in order to ensure that users are aware of possible health risks associated with the substance.

Another concern is that cannabis producers could use advertising to compel widespread usage of the drug, similar to what occurred with tobacco and alcohol in the past.

But the licensed producers say they aren't looking to lure people into consuming marijuana. Instead, they wish to use branding and in-store advertising to educate users about various strains and their impacts, according to the letter.

"No one in this industry is looking to repeat the same mistakes as tobacco or alcohol," says Kennedy. "No one wants to see a Joe Camel of this industry."

Cannabis producers also take issue with the tax force's recommendation that medical and recreational cannabis be taxed the same amount.

This would "unduly burden" medical cannabis patients, according to the companies, who argue that medical cannabis should be sold tax free.

"Other pharmaceutical products aren't taxed," says Kennedy.