OTTAWA -- Some of Canada's largest, most influential environment groups say their confidence in the Liberal government's commitment to sustainability is beginning to wane.

With the 2019 election less than 18 months away, a new report from a dozen environmental lobby groups and charities is casting doubt on the Trudeau government's progress to date on many of the promises from the 2015 campaign and mandate letters issued to cabinet ministers.

The groups -- including the Pembina Institute, now run by former Ontario Liberal environment minister Glen Murray; Greenpeace; the David Suzuki Foundation; and the Canadian Parks and Wilderness Society -- say in many areas, the government kept its promises in principle, but not really in execution.

"When the new federal government took office in 2015, it arrived with a great deal of optimism and promise," says the report. "Their campaign language had raised the expectations of many sectors, including the one fostering sustainability in Canada."

The groups are largely content with progress on the Paris climate change accord, regulations to cut methane emissions from the oil and gas sector, the phase-out of using coal to generate electricity and the fulfillment of a promise to phase out hydrofluorocarbons.

Hydrofluorocarbons, used in air conditioners and refrigeration as an alternative to ozone-depleting substances, are the fastest-growing category of greenhouse gas emissions in the world, substantially more toxic to the climate than carbon dioxide.

The report cheers the government for giving Canadians a voice in government policy, something they say has occurred for "virtually all issues" they raise in their report.

"There has been a sea change in Ottawa when it comes to seeking and listening to voices concerning the protection of the environment," it says.

"The government has asked independent experts to serve on panels, commissions and advisory committees in developing new environmental policy."

On a number of other commitments, however, the group is less than pleased.

They cite a lack of action on phasing out fossil fuels and continued support for building new pipelines and expanding oilsands production. Ottawa and the provinces spend about $3 billion a year on measures like tax credits and special deductions for the oil industry, or even sometimes direct cash payments.

In their platform in 2015, the Liberals made a clear commitment to "phase out subsidies for the fossil fuel industry over the medium term," but the report says there's been no movement on that to date -- indeed, the government has locked in some subsidies for at least another decade, it notes.

They also say the government's new environmental assessment legislation falls short of its claims to reintroduce clarity and science to the process.

The report also gives a failing grade to action on national parks management, noting nearly half of ecosystems in national parks are in fair or poor condition and the Parks Canada conservation mandate needs a better focus and funding.

It also raises a red flag about the government's commitment to allowing charitable groups that engage in non-partisan advocacy work to avoid Canada Revenue Agency audits for spending too much on political work.

The Liberal government did suspend audits of charities started by the previous Conservative government, but charities are anxious to see the laws amended to prevent what they say was a politically motivated attempt to silence groups critical of government policy.

The report also hails the government's amendments to the Fisheries Act to restore protection for fish habitat and with $1.3 billion in the 2018 budget to increase the amount of land and water that is protected in Canada.