Premier Jason Kenney is rejecting concerns from an environmental legal advocacy group about bias and a lack of fairness in the public inquiry into foreign funding of critics of Alberta`s oil and gas industry.

Ecojustice lawyers Barry Robinson and Kurt Stilwell sent a letter on Tuesday to Steve Allan, the forensic accountant who is leading the inquiry, that threatens to take legal action.

Robinson and Stilwell said the current terms of reference are unlawful and have the potential to be deemed unconstitutional. The lawyers made eight suggestions on how to make the process fair to everyone asked to take part.

On a teleconference from New York City on Wednesday, Kenney said he hadn't read the letter but called the response "entirely predictable" and a "regurgitation" of the "laughable" letter sent last week by Amnesty International, which also criticized the inquiry.

"I understand why these groups are hyperventilating," Kenney said. "These responses confirm that we are on exactly the right track."

Kenney's office followed up with an email pointing to the financial information Ecojustice filed with the Canada Revenue Agency. It shows the group received money from foreign sources, including $1,046,974 from Nov. 1, 2017, to Oct 31, 2018, and $730,984 the year before that.

The inquiry has a mandate to find out how much foreign money has funded environmental campaigns against Alberta oil and gas.

Opponents say the inquiry, which was promised by Kenney during the spring election campaign, is intended to stifle legitimate public criticism of the oil and gas industry in light of the effects of climate change.

Ecojustice said the terms of reference raise reasonable apprehension of bias in the inquiry as it lays out a predetermined result before any evidence is called.

Robinson and Stilwell suggested the terms of reference be changed to make the process fairer to the groups who may be called to testify.

The suggested changes include: giving people the right to legal counsel; allowing them to call witnesses and table evidence; permitting cross-examination of testimony; and making transcripts of the commissioner's interviews available to all parties.

Allan is in the first stage of his inquiry and is gathering documents and interviewing potential witnesses. He has the option of calling a public hearing.