The national fuel carbon standard that would make each litre of diesel and gasoline sold in Canada a little greener won’t be ready when it was promised, but Environment and Climate Minister Catherine McKenna says it’s still in the works.

It was a big moment when McKenna announced last year that Canada would set a new requirement for vehicle fuels that would limit the carbon released to the atmosphere when they burned. She said the effect would be like taking 6.4 million cars off the road, cutting 30 megatonnes from Canada’s emissions by 2030.

That would get the country more than one-third of the way to the emissions reductions it has targeted under the Pan Canadian Framework on Clean Growth and Climate Change, adopted by Prime Minister Justin Trudeau and most provincial and territorial premiers last December.

“This clean fuel standard will be a made-in-Canada approach that will provide flexibility to industry in how they innovate, and reduce emissions throughout the fuel system,” McKenna said last November.  “It will stimulate Canadian production of renewable biofuels from the agriculture sector, and use lower-carbon fossil fuels such as natural gas.”

A year of consultation was supposed to deliver a draft regulation about now, to allow affected industries to provide feedback, with a final version to come into effect next year. But McKenna will now say only that the draft is on its way—with no promise that it will be revealed this year.

“It’s a really important piece of our climate plan,” McKenna maintains. “We know that we can have cleaner fuels. There is an economic opportunity. The details will be coming out soon.”

Whatever clean fuel standard is enacted, it will most likely be met by blending plant-derived biofuels into gasoline—as the United States requires with an ethanol content standard. It could add as much as $5 per month to the average Canadian’s expenses, Clean Energy Canada estimates. In British Columbia, which has had a provincial fuel carbon standard since 2010, “most British Columbians aren’t even aware it exists, yet it resulted in one-fourth of B.C.’s emissions reductions between 2007 and 2012,” the group states.

Late delivery of a draft federal regulation makes it less likely the government will meet its goal of requiring cleaner fuel at Canada’s gas and diesel pumps by mid-2018.