Brian Mulroney says that Donald Trump’s proposal to rip up the North American Free Trade Agreement would push more Mexican migrants into the United States at a time when the potential U.S. president is determined to keep them out.

The former Progressive Conservative prime minister told CTV’s Question Period that Trump has “tapped into a well of unhappiness in the United States which surrounds illegal immigration.”

“But the way you deal with that is,” he said, “is to enforce your laws of course, but also to ensure that more wealth is created south of the border.”

“That keeps young Mexicans at home -- they don’t want to go to the United States in that case.”

Mulroney said that’s already happening, and he credits NAFTA, which he said has created “millions and millions” of jobs across the three-nation bloc since he signed it in 1992.

“Ironically, at this particular time in history, there are more young Mexicans staying at home than coming into the United States,” he added.

Indeed, Pew Research Centre figures show that between 2008 and 2014 about 870,000 Mexicans legally moved to the U.S., while about 1 million Mexicans returned to Mexico. That’s compared to nearly three million Mexicans migrating to the U.S. between 1995 and 2000, when only about 670,000 returned.

In terms of unauthorized or illegal immigrants from Mexico, Pew estimates the total number in the U.S. fell by about one million from around 6.6 million in 2007 to about 5.6 million in 2014.

The former prime minister told Question Period that although Trump’s anti-immigrant rhetoric “carried him through the Republican primaries, he doesn’t think “something that negative carries you through to the White House.”

Democrat Hillary Clinton has also talked tough about free trade -- as did President Barack Obama, who later went on to propose expanded free trade through the Trans-Pacific Partnership.

Mulroney said he “can’t conceive of a situation whereby Mr. Trump or Mrs. Clinton or anybody else could get away with (ripping up NAFTA),” adding “Congress or the American people wouldn’t allow it.”

Mulroney seemed more concerned in June, when he told CTV’s Power Play that Trump’s economic proposals would push the United States into a “depression very, very quickly.”

Mulroney added that he thinks Prime Minister Justin Trudeau should move “as quickly as he can” on a free trade agreement with China.

Canada and China agreed earlier this week to a feasibility study on a possible free trade deal, according to the Chinese premier.

A recent survey conducted for the Asia Pacific Foundation found that an equal number of those polled – 46 per cent -- support and oppose a free trade agreement with China.