A letter-writing campaign calling for an end to Country of Origin Labeling (COOL) is hitting the U.S. Senate.

News reports suggest about 250 American companies and trade associations have sent a letter to every senator calling on them to repeal the legislation. A recent World Trade Organization ruling in favour of Canada and Mexico has opened the door to $1 billion in new annual tariffs on American goods in retaliation for the mandatory labeling law, which has cost the Canadian beef and pork industries billions of dollars since it was first introduced in 2009.

During a visit to Regina last month, Linda Chezen with the U.S. National Cattlemen Association talked about her support for labeling.

"I have no problem with repealing it, I do have a problem with not labelling the source of food because we also freely import from other countries, not just Canada," she says.

Bill Baldwin with the Nebraska Farm Bureau also shared his thoughts while attending Agribition in Regina last month.

"American Farm Bureau's current policy is we support COOL, if it supports the parameters of the WTO (World Trade Organization), which is doesn't, so basically I guess we don't support COOL," he says.

Canada’s International Trade Minister Chrystia Freeland and federal Agriculture Minister Lawrence MacAulay said this week if the U.S. senate does not take immediate action to repeal COOL for beef and pork, Canada will quickly take steps to retaliate. There are plans to have the tariffs in place before the new year.