New Brunswick Premier David Alward says federal Liberal Leader Justin Trudeau is "50 years late" in arguing for research into the effects of fracking, the method used to extract shale gas.

Alward, who as leader of the New Brunswick Progressive Conservatives is in the middle of an election campaign in his province, spoke at a press conference in Charlottetown, where he's at a meeting of Canada's premiers.

Alward said Trudeau wants Canada to stop developing shale gas until more scientific work has been done.

"Justin Trudeau is 50 years late. The reality is the scientific work has been taking place over the last 50 years," Alward said.

"Fracking has been taking place safely across our country for the last 50 years and the reality [is that] Canadian technology, research and innovation is allowing the rest of the world to compete."

The Canadian Press reported last Saturday that Trudeau said more study was needed before expanding shale gas developments.

A spokeswoman for Trudeau said his remarks were based on a recently released report by Environment Canada and the Council of Canadian Academies that said the research done so far is insufficient.

"Mr. Trudeau was very clear in his comments that science needs to inform how we proceed with development, which is exactly what the CCA report suggests," Kate Purchase said in an email.​

'Neither sufficient nor conclusive'

Alward says New Brunswick needs job opportunities for residents, tens of thousands of whom, he said, are "living outside our province, building economies in other parts of Canada."

Alward spoke to journalists along with British Columbia Premier Christy Clark after the two signed a labour market mobility agreement. His comments about Trudeau weren't prompted by a question.

Fracking is the name for the process that extracts gas by fracturing rock beds with high-pressure fluids.

Last spring, the report by Environment Canada found that Canadian "data about potential environmental impacts are neither sufficient nor conclusive."

Last fall, the New Brunswick Liberals called for a moratorium on shale gas development. Trudeau, campaigning with provincial Liberal leader Brian Gallant last weekend, said more scientific study is needed before expanding shale gas development.