HALIFAX - The Nova Scotia government is putting a two-year hold on hydraulic fracturing, saying it needs more time to study a controversial oil and gas industry practice that has raised concerns about contamination of drinking water.

The government had planned to release a review of the industry this spring, but it announced Monday that the report has been put off until mid-2014, prompting critics to suggest the ruling NDP is trying to avoid the issue until after the next election, expected as early as next spring.

"They don't want to have to deal with it at the moment because it is politically sensitive and charged," said Liberal critic Andrew Younger.

Ken Summers, a member of the Nova Scotia Fracking Resource and Action Coalition, came to the same conclusion.

"The one year that they had allowed for the review was, in our opinion, never enough time," he said in an interview from his home in Minasville. "Merely taking another year doesn't necessarily mean anything except it takes us past the next election."

Summers lives in an area of the province where at least two test wells have already been fracked.

Premier Darrell Dexter dismissed the election talk.

"On this decision, I don't really think it matters when there is an election. This is about doing a scientific review and coming up with the right decision on it based on the science."

A spokesman for the Calgary-based Canadian Society for Unconventional Resources, an industry advocacy group that promotes hydraulic fracturing, could not be reached for comment.

As of Monday, no fracking will be approved during the extended review, said Environment Minister Sterling Belliveau.

Energy Minister Charlie Parker said the government wants to study reviews being drafted by the U.S. Environment Protection Agency and Environment Canada. As well, New York State, Quebec and New Brunswick are also studying the effects of fracking, he said.

"We think it's important to get the best possible information that's out there and make an informed decision after we've learned all that," said Parker.

In neighbouring New Brunswick, fracking has become a hot-button issue, complete with high-profile protests, petitions and government pledges to introduce tougher environmental legislation.

Hydraulic fracturing, or fracking, involves blasting a mixture of water, sand and chemicals into a well bore to fracture the surrounding rock and release the trapped hydrocarbons, usually natural gas, coalbed methane or crude oil.

Critics say the process threatens drinking water supplies by allowing the migration of noxious gases and chemicals into the water table.

The industry says the process is safe, noting that over a million wells have been fracked in North America since the 1940s.

But industry critics say it's wrong to compare the older fracturing process with so-called high-volume hydraulic fracturing used on shale deposits -- a process that has grown in popularity since the 1990s.

Jennifer West, co-ordinator for the Nova Scotia Fracking Resource and Action Coalition, said she was encouraged by Nova Scotia's move.

However, she said her group would prefer a full-fledged moratorium backed by provincial legislation.

West said the government has come to realize that the impact of hydraulic fracturing on the environment is a complex issue.

"They now realize, having waded in so far, that there's sharks in the water," she said. "It has so many suspicious and suspect side effects. ... At first it looked like low-hanging fruit, but it's more difficult than that."

Earlier, Parker issued a statement responding to concerns expressed by opponents of fracking.

"I have talked to many Nova Scotians who are concerned about their drinking water and the implications of injecting sand, chemicals and large volumes of water into the earth," the statement said.

"They have questions and concerns and we will take time to learn from jurisdictions with significantly more experience in this area than Nova Scotia."