The Minister of Natural Resources was in Edmonton Friday, and while he showed support for Alberta's oil sands – he blasted some of the industry's most outspoken critics.

Minister Joe Oliver spent the morning speaking with Premier Alison Redford – before appearing with her before the press, throwing his government's support for the energy sector.

Later on, he addressed the Alberta Chambers of Commerce, and expressed the same sentiment.

"We're talking over the next 25 years, of $3.3 trillion in economic activity," Oliver said.

"The oil sands, the world's third largest proven oil reserves are responsible directly and indirectly for the jobs of some 400,000 people across Canada."

The public show of support from the federal Conservatives comes not long after controversial remarks made by the federal NDP leader – where he said the oil sands were hurting the manufacturing sector.

"The Canadian dollar is artificially high because we are letting these companies – especially the oil sands – use the air, the soil, the water as a dumping ground," NDP Leader Thomas Mulcair said on May 16.

"He just doesn't understand Canadian economic history," Oliver said in response.

However, some critics said Oliver's visit was ill-timed, pointing to a recently discovered oil leak near Rainbow Lake.

"It's definitely very ironic with the minister in town to promote the tar sands industry and new pipeline construction, that we would be dealing with another major oil spill," Greenpeace spokesperson Mike Hudema said.

A spokesperson for Pace Oil and Gas told CTV News crews are working on cleaning up the 22,000 barrel oil leak.

"We were able to get men on the ground quickly," Fred Wood said. "Right now we have about 40 people on site cleaning it up."

To prevent future leaks, Oliver said Ottawa is working on ways to catch possible problems early.

"We're increasing by 50 per cent the number of pipeline inspections, and doubling the annual audits for pipelines," Oliver said.

With files from Bill Fortier