“Without changing these definitions, some of Canada’s fastest growing agricultural sectors, including greenhouse vegetable production, would not be captured under the exemption for farms.” The Trudeau government has drafted what it says is a revenue-neutral carbon tax of $10 per tonne in 2018, rising to $50 per tonne by 2022, for any province that has not signed on to the Pan-Canadian Framework on Clean Growth and Climate that requires provinces create a carbon tax or cap-and-trade system of their own by September 1. All provinces have said the tax will not apply to marked farm fuels, commonly known as ‘purple’ gas and diesel. British Columbia’s plan also includes an exemption for most natural gas used within the greenhouse industry.

However, the federal government’s plan included within Budget 2018 does not include an exemption for natural gas and propane used on farms — fuels that are used daily for things like heating and cooling barns, running farm equipment and drying grains post harvest.

Meanwhile, the current legislation’s definition of ‘eligible farming machinery’ includes tools like tractors and farm trucks and a prescribed property.

That definition, the three farm groups argue, does not include property that provides “heating or cooling to a building or similar structure for agricultural production” like greenhouses or livestock barns.

They want that changed, noting “as farmers constantly modernize and evolve their farming activities to keep up with global competition, we want to ensure all farmers will be eligible for the farming exemption.

On Monday, Senate Agriculture Committee Chair Diane Griffin said she supports the groups’ requests and urged her colleagues on the National Finance Committee to take them under advisement.

“Senators, I agree with these three sensible suggestions by farmers,” she said.

Finance Minister Bill Morneau was scheduled to appear before the Senate finance committee Tuesday to discuss his budget plan, which is currently being studied by the committee.

The letter from the farm community also comes as Agriculture Minister Lawrence MacAulay continues to face criticism after he told the Senate last week most Canadian farmers support Ottawa’s carbon plan.

“I have to reiterate that farmers are caretakers of the lands and waters, and you would find that most farmers support the moves we have made to make sure that we put a tax on carbon,” he said in response to a question May 29 from New Brunswick Senator Carolyn Stewart Olsen about the cost of the Liberal carbon tax on farmers.

The majority of Canadian farm groups are staunchly opposed to the Liberal government’s proposed carbon tax.

On Monday, MacAulay tried to clarify his remarks, telling the House of Commons he is aware farmers have concerns about the policy and said that’s why Ottawa has issued an exemption for ‘purple’ gas and diesel.

The Trudeau government has said it will impose its carbon pricing plan on any province that does not meet the September 1 deadline. The Saskatchewan government, which is strongly opposed to a carbon tax, is challenging that position in court.

Saskatchewan has cited competitiveness concerns within the agriculture industry as one of the reasons it opposes the Trudeau government’s carbon plan.

Environment Minister Catherine McKenna’s office said in December 2016 that Saskatchewan farmers would be eligible for the same exemptions currently in place for producers in British Columbia if the province does not agree to a national carbon price plan.