EDMONTON -- Federal NDP Leader Thomas Mulcair says a judge's finding that Alberta's Environment Department has been covertly working to silence oilsands critics reinforces widespread cynicism that the province's approval process for projects is rigged.

"It's a very damning analysis of what's been going on here," Mulcair told reporters Thursday after meetings at the University of Alberta.

"To have a judge come out so clearly and to say that there's an absolute breach of the fundamental rules of natural justice in the process simply reinforces the perception of a lot of Canadians in general -- and a lot of Albertans in particular -- that the dice have been loaded."

On Tuesday, Court of Queen's Bench Justice Richard Marceau said Environment Department bureaucrats contravened their own laws by enacting a shadow policy in 2009 to stop the Oil Sands Environmental Coalition from speaking to reviews of proposed oilsands operations.

Marceau, in his ruling, pointed to a 2009 briefing note from the department's northern region director to the top bureaucrat in the department at the time, deputy minister Jim Ellis.

The note said that while the coalition had been given standing in previous oilsands hearings, that should stop.

It said the coalition was no longer assisting the government on environmental initiatives and that one member of the coalition in particular, the Pembina Institute think-tank, was publishing "negative media on the oilsands."

The director, who is not named in Marceau's judgment, suggested the coalition be rejected on the grounds it is not directly affected by the oilsands operations.

Marceau found that in June 2012 the director indeed used those grounds to reject the coalition's application for standing on a Southern Pacific Resource Corp. oilsands in situ drilling operation south of Fort MacKay.

Two members of the coalition, Pembina and the Fort McMurray Environmental Association, appealed the decision, leading to Marceau's decision this week to quash the government's rejection of the coalition.

In his ruling, Marceau noted that nowhere in Alberta's Environmental Protection and Enhancement Act does it say the government can exclude from reviews "those persons or groups who voice negative statements about proposed oilsands development."

The government has yet to decide if it will appeal.

Simon Dyer of the Pembina Institute has said they don't reject the oilsands operations outright, but want to see the industry developed in an environmentally responsible way.

Mulcair said the issue demands immediate action.

"The minister responsible should come back and tell people how it is that a process is put in place that simply doesn't respect the basic principles of natural justice," he said.

"People have a right to know that the environment is being protected."

McQueen is in Europe this week trying to convince European Union leaders to not place a sanction on oilsands crude based on research showing it is more harmful to the environment than conventional oil.

In a statement released Thursday afternoon, McQueen did not address Marceau's ruling directly except to say "the NDP prefers to live in the past referring to documents from five years ago."

McQueen's statement also did not address Marceau's key finding that while the memo was drafted in 2009, it was being acted upon by environment bureaucrats as late as June 2012, on McQueen's watch.

"Mr. Mulcair and his provincial cousins have made a habit of putting politics ahead of facts when talking about Alberta and the oilsands. The NDP have gone out of their way to undermine the good work done," the statement read.

The provincial NDP has called for the resignation of Ellis, who is now the CEO of the Alberta Energy Regulator, which oversees the regulation of all energy projects in the province.

Ellis was unavailable for an interview Thursday, but in a statement issued through the regulator said the issue begins and ends with the northern region director.

"The briefing note referenced in the court's decision stated it was prepared for 'information purposes' and was intended to inform the deputy minister of a decision that had been made by the director as decision maker," read the statement.

"There is no inference or explicit indication of interference, involvement or influence by the either the deputy minister or minister in the decisions made by the director on this matter."

The statement does not spell out what, if any, reply Ellis had to the briefing note or if he took any action given it made clear the director was seeking to reject the coalition for reasons outside legislation.

Alberta NDP Leader Brian Mason said McQueen refuses to take responsibility for actions that took place on her watch.

"The role of government and government regulators is to ensure the interest of Albertans is best protected, not the interest of oil companies.

"Instead of attacking the NDP, Minister McQueen needs to answer to Albertans for her ministry's role in circumventing the law," Mason said in a news release.

Provincial NDP environment critic Rachel Notley said Ellis's actions are "worse than a cop-out."

"The deputy has to take responsibility for things about which he is informed," said Notley.

"He doesn't take direction from his staff. It works the other way around, and no regular Albertan is going to believe anything other than that."

Mulcair said the cynicism that results from issues like Marceau's ruling has far-reaching consequences for government and industries seeking to build public support for other controversial, big-ticket projects, such as pipelines.

"You can't get to yes on any of these projects unless there's social buy-in. You can enforce the rules, and change them in such a way that you get the regulatory licence even faster, (but) in absence of a social licence they're not going to be built," he said.

One such big-ticket project is the Keystone XL pipeline, which has become a political lightning rod in the United States.

Premier Alison Redford has made numerous trips to Washington in recent months to rally support for Keystone, which would take oilsands bitumen across North America to refineries on the Gulf Coast in Texas.

U.S. President Barack Obama is expected to rule on Keystone later this year or in 2014.

Alberta has also met fierce resistance from environmental protesters who fear the consequences of a pipeline spill from the proposed Northern Gateway pipeline, which would take crude from the oilsands across B.C.'s wilderness to tankers on the coast.

Redford has said Alberta has a first-class regulatory system and is a leader in environmental initiatives to limit the impact of the oilsands on air, land, and water.