The Canadian government is to mark the 25th anniversary of its green business advisers by closing the agency down.

John Baird, Canada's foreign affairs minister and pointman for next month's Rio+20 Earth summit in Brazil, said this week that the National Roundtable for the Environment and Economy (NRTEE) would have its funding cut in 2013 because of the availability of information from thinktanks, the internet and universities.

Baird told reporters that Canadian taxpayers should not have to pay for an organisation that has produced 10 reports promoting a carbon tax – "something that the people of Canada have repeatedly rejected".

"But that's not correct," the Roundtable's CEO, David McLaughlin, told the Guardian on Thursday, adding that it had never advocated a carbon tax but had looked at cap and trade for regulating Canada's greenhouse gas emissions in a 2009 report commissioned by the government. "Which was government policy at the time," said McLaughlin.

McLaughlin, a former chief of staff to federal finance minister Jim Flaherty, stressed there was always original analysis in its reports, making available information that would not otherwise be in the public domain. McLaughlin also pointed to the Roundtable's ability to combine research while convening people from industry as well as the environmental sector together.

Only on Wednesday the NRTEE provided an environmental life cycle analysis commissioned by the federal environment minister, Peter Kent, and a climate change report is due out next month that will look at provincial emissions reduction plans.

The C$5.2 million funding for the NRTEE will cease as of 31 March next year under a wide-ranging omnibus budget bill C-38 that is currently before Canada's House of Commons. The legislation seeks to speed up natural resources projects such as oil and gas pipelines, and repeal the Kyoto Protocol Implementation Act.