CALGARY -- Mario Reyes choked back tears on Wednesday while discussing his last-ditch attempt to remain in Canada as the clock ran out for thousands of temporary foreign workers like him whose work permits have expired.

Reyes, who came to Canada from the Philippines seven years ago, has been working at a Minit Lube franchise in Red Deer, Alta., as a temporary foreign worker. He's now facing the reality that he will soon have to return home.

"When I was in the Philippines, life was really hard for me, but when I got a chance to work here everything changed," said Reyes at his lawyer's office in Calgary.

"I was able to send my kids to school because life in the Philippines is hard. If I go back to the Philippines, my girls cannot finish their studies and it's going to break their hearts."

Reyes turns 48 later this month. His application for permanent residency, filed last November, has been rejected and his hopes of eventually becoming a Canadian citizen are in jeopardy.

"It's Canadian first; I understand," said Reyes.

"It's Canadian first, but I deserve to stay. I pay my taxes, I work hard, I do not break the law. I deserve to be a Canadian or at least a permanent resident."

In 2011, the Conservative government set April 1, 2015, as the deadline for temporary foreign workers in low-skilled jobs to either become permanent residents or return home.

In Alberta alone, 10,000 temporary foreign workers have applied to stay in Canada.

Immigration Canada hasn't divulged the total number of workers who now must leave, but immigration and labour market experts have estimated tens of thousands are affected.

Peter Wong, Reyes' lawyer, said he represents more than 30 workers in similar circumstances.

Wong is trying to buy them some time in the hope that government officials will issue what he calls a "rare exception."

"There are lots of what I would call very desperate attempts to remain in Canada after that April 1 deadline," Wong said. "Some will work. The vast majority will not and that's the sad reality."

Vanessa Routley, a Toronto immigration lawyer, was critical of the deadline, saying it unfairly targets the lowest-paid and lowest-skilled, leaving executives and engineers unaffected.

"Rather than offering these hard workers a pathway to permanent residence where they could continue the low-skilled jobs nobody else wants, the Canadian public has been sold a line that exchanging one legion of temporary workers for another every four years is a solution."

In Ottawa, Employment Minister Pierre Poilievre defended the government's position.

"Our policy is that Canadians should come first for Canadian jobs," Poilievre told reporters.

"The April 1st deadline has been known for a very long time and the purpose of the program is for it to be temporary. That's why they're called temporary foreign workers."

Businesses should raise wages and hire Canadians if they're struggling to fill positions, he added.

Several organizations, including the Canadian Federation of Independent Business and the Alberta Federation of Labour, have called for an easier path to permanent residence and eventually citizenship for temporary foreign workers, especially those employed in provinces with labour shortages.