Former Tory Prime Minister Brian Mulroney says Canada cannot function without foreign investment.

While attending a function in Calgary Tuesday night, Mulroney told reporters foreign investment is the only way to help grow the Canadian economy, especially when it comes to oil and gas development.

Earlier in the week, the federal government rejected the $5.2-billion foreign takeover of Progress Energy Resources of Calgary.  

Malaysian state-owned Petronas has been given 30 days to re-work its offer.

Next month, Ottawa will also rule on the proposed $15-billion takeover of Nexen by the China National Offshore Oil Company.

Mulroney also predicts the controversial and much-delayed Keystone XL Pipeline project from Alberta to the American Gulf Coast will be approved no matter who wins next month’s presidential election.

He calls the almost $7-billion a development a no-brainer.

Meanwhile, the Macdonald-Laurier Institute has published a study that suggests future economic growth hinges on Canada getting its oil to Asia.