TORONTO - Biofuels derived from crops such as corn and canola might have the support of Canadian governments but activists say a growing reliance on the technology represents a real threat to the environment and the global agriculture sector - a warning they plan to take across the county.

While the cross-Canada information tour is aimed at the "dangers" of biofuels, the Canadian Biotechnology Action Network (CBAN) fears its message comes too late to influence proposed federal legislation to increase reliance on the alternative energy.

The bill - an amendment to the Environmental Protection Act - would require gasoline, diesel and heating oil to contain minimum amounts of biofuel, a renewable energy source derived from plants and often referred to as agrifuels.

While a five per cent ethanol requirement in gasoline, for example, is already mandated in some provinces it's been criticized of late given the rising cost of food - a worldwide phenomenon critics say is driven in part by the growing demand for biofuels.

"This is a critical time when it comes to both how we deal with energy policy and how we deal with food policy," said Devlin Kuyek, a researcher with Montreal-based NGO Grain. "Rushing into this biofuels craze is, I think, very premature."

Beginning April 28 with stops in Charlottetown, Saskatoon, Winnipeg, Halifax, Ottawa and Montreal, the tour's slate of international speakers will talk about how the "global conflict over the production of crops for fuel" is devastating farmers and leading to mass deforestation, said CBAN co-ordinator Lucy Sharratt.

Touted by supporters as an environmentally friendly energy source and the natural answer to climate change, Sharratt said biofuels often have the opposite effect.

It displaces food crops, requires large amounts of fertilizer and water, uses fossil fuels in production and is essentially "an industrial process," she said, noting it has to be, to the detriment of small farmers, in order to meet the mandates governments are putting forward.

Since Canada isn't likely to meet those mandates internally, it will have to import biofuels made from Brazilian sugar cane or Indonesian palm oil, Sharratt added.

That means Canada will be supporting deforestation, pesticide poisoning and the often violent eviction of small farmers to make way for large-scale plantations in such countries, she said.

Third reading of the bill is expected before the end of the month and with both the Conservatives and Liberals poised to support it amid little public debate, any pressure to restrict the use of biofuels will have to come in the regulations.

The production of food crops like corn and canola for ethanol and biodiesel already exists in Canada and are often subsidized by government. In 2005, Ontario committed $520 million over 12 years to support ethanol production. British Columbia, Saskatchewan and Manitoba have also set ethanol mandates and the federal government has committed $1.5 billion over seven years to support the development of renewable fuels.

Calling the latest bill a mere "technical amendment," Liberal environment critic David McGuinty said his party would actually prefer a much stronger 10 per cent ethanol mandate but is prepared to support the legislation.

Although he's voiced concerns already in the House of Commons, he expects there will be far more debate when it comes time to draft the regulations.

"I'd like to see us make a quantum leap to cellulosic biofuel," McGuinty said, noting it's made from certain types of straw and grass instead of corn and other edible grains.

"It's a cleaner burning fuel, it has fewer environmental impacts and it isn't taking, necessarily, the best agricultural land out of production for other feed stuffs."

What types of biofuels Canada should support and what restrictions might be imposed on imports are all matters to be discussed later, he said, adding the technology can't be dismissed outright.

"Environmentalists and purists will have us say, 'well, we shouldn't be doing any of this.' Then they'll tell us that we shouldn't have nuclear... that we shouldn't have fossil fuels and then you get to a point where you say, 'well what is it?' "

Among the few political voices to oppose the bill, New Democrat and agri-foods critic Alex Atamanenko said he proposed several changes to the legislation, all but one of which was rejected.

The agriculture committee has agreed to review the environmental and economic impact of biofuel production in Canada six months after the legislation comes into effect and every two years thereafter.

"My fear is that it goes against all the latest research coming out that's saying that we should be thinking very carefully before we support a biofuels policy," Atamanenko said.

"We need more thought and discussion to see if in fact in 10 years from now we can look back and say we've made the right decision."