A left-leaning think tank on Tuesday decried Big Oil's rising influence on Canadian government policies, citing a whopping 2,733 meetings with public officials since 2008 versus a few with environmentalists.

The Ottawa-based Polaris Institute called for a public inquiry to "investigate the influence of the oil industry" on the government.

In a report entitled "Big Oil's Oily Grasp -- The making of Canada as a petro-state and how oil money is corrupting Canadian politics," the Institute said lobbying by the oil industry spiked in the lead-up to major regulatory changes that critics say gutted environmental protections.

Using data compiled from an official lobby registry, the report says that the oil and gas sector's access to Prime Minister Stephen Harper's government out-stripped other industries such as auto manufacturing and mining.

"The amount of face time the oil industry gets in Ottawa in personal meetings and other correspondence greatly exceeds the time afforded other major industries in Canada," said report co-author Daniel Cayley-Daoust.

"No one doubts the hold the oil industry has on this current government, but it is important Canadians are aware that such a high rate of lobbying to federal ministers has strong policy implications."

The report shows six main oil industry players, including Enbridge and TransCanada, met with 52 federal cabinet ministers between September 2011 and September 2012. It also shows an increase in lobbying from the pipeline industry.

Greenpeace is the only environmental group to have met with Natural Resources Minister Joe Oliver in March, 2012, according to the report.

The oil industry is vying to build an expansive pipeline network connecting the Alberta tar sands to new overseas markets, as its sole customer, the United States, seeks to reduce its dependence on foreign oil.

Industry executives told local media their talks with the government tend to be broad-ranging, including issues such as environmental, aboriginal affairs, and international trade.

Oliver's spokesman called the report "false" and "misleading."

Spokesman Chris McCluskey said in an email that Oliver "regularly meets with a variety of stakeholders and just last week met with a coalition of environmental groups."

These included the Green Budget Coalition, the Pembina Institute, the David Suzuki Foundation and Ecojustice Canada, he said.

Those talks were not recorded in the data because, unlike industry associations, most environmental groups are not required to report their ministerial meetings to the commissioner of lobbying.