OTTAWA -- A high-powered group of external advisers is calling for a dramatic increase in Canada's immigration levels, but Immigration Minister John McCallum says that might be too ambitious.

McCallum said Wednesday he's read the report by the Advisory Council on Economic Growth that calls for a 50-per-cent increase in targets to 450,000 people a year.

The measure would target skilled, entrepreneurial newcomers in an attempt to stimulate economic growth.

The 14-member panel, chaired by Dominic Barton of the firm McKinsey and Co., is to deliver a set of recommendations to Finance Minister Bill Morneau on Thursday.

McCallum said meeting the target suggested by Barton's group would be costly and might not find broad national support.

"The figure he gives is a huge figure," McCallum said. "But this is not a universal view across the country."

Discussions are continuing and the government will announce immigration targets for 2017 next month, McCallum added.

McCallum's cabinet colleague, Economic Development Minister Navdeep Bains, told The Canadian Press on Wednesday that he's "worked very closely" with Barton's panel, and favours increased immigration levels. But he stopped short of endorsing the target in Barton's report.

"Clearly he's demonstrating an opportunity for Canada," Bains said. "We value our diversity, we value our multicultural society and we recognize immigration is an opportunity to create jobs."

Bains said the government would need to sell the idea of higher immigration levels to the public.

"We, as a government, need to focus on communicating the benefits of growing the economy and part of that growth is investing in people and part of that equation is immigration."

Bains said bringing in more skilled workers is part of the government's broader agenda that includes investing in research and development, creating jobs and helping companies grow.

A survey released by Canadian Manufactures and Exporters said the most pressing challenge facing its member companies is "attracting or retaining skilled labour."

The response came from a survey and roundtable discussions with 1,300 member companies.

Matthew Wilson, the organization's senior vice president, said manufacturers have traditionally looked beyond Canada's border to find skilled workers.

"If we can expand that, that's good," he said in an interview.

But the government needs to do more to make sure the immigrants they allow into Canada actually have skills that are needed, Wilson added.

"Just bringing in more immigrants isn't going to solve the skills-gap problem if they don't have the skills Canadian companies need."

The continuing need to address the country's sluggish economy was underscored Wednesday as the Bank of Canada downgraded its growth prediction.

The bank's latest outlook projected a real GDP expansion of 1.1 per cent this year, down from its earlier 1.3 per cent forecast.

Governor Stephen Poloz listed immigration as "one of the ingredients" for helping to reverse declining growth.