OTTAWA -- Prime Minister Justin Trudeau is defending controversial changes to asylum laws included in an omnibus budget bill tabled this week, saying his government wants to ensure Canada's refugee system is fair for everyone.

The changes would prevent asylum-seekers from making refugee claims in Canada if they have made similar claims in certain other countries, including the United States -- a move Border Security Minister Bill Blair says is aimed at preventing "asylum-shopping."

Lawyers and advocates who work with refugees are sounding the alarm about the legal changes, saying they would strip human-rights protections from vulnerable asylum-seekers.

Trudeau said Wednesday that Canada has been seeing larger numbers of refugee claims because of global instability. Sustaining Canadians' confidence in the country's asylum system means ensuring those who enter Canada must do so according to the law, he said.

"That's why we're putting more resources in, and we're also ensuring the system is fair for everyone," he told reporters on Parliament Hill.

More than 41,000 asylum-seekers have crossed into Canada "irregularly" through unofficial paths along the Canada-U.S. border since early 2017. By doing this, they take advantage of a loophole in Canada's "Safe Third Country Agreement" with the United States that allows refugees who find a way to get to Canada by avoiding official border checkpoints to make refugee claims in Canada. The agreement would otherwise see them turned back to the U.S. -- a country Canada officially considers safe for them.

The influx of irregular migrants began after U.S. President Donald Trump announced he would end a program that offers temporary protected status to migrants from several countries. It has become a difficult political issue for the Trudeau government as hundreds of migrants continue to arrive in Canada through an unofficial crossing in Quebec each month.

The Liberals signalled their intent to get tougher on the border in the 2019 budget, which included a plan for $1.18 billion over five years to beef up security and law enforcement and speed up the processing of asylum claims.

Finance Minister Bill Morneau said Canada wants to maintain its reputation as a fair and welcoming country, but also one that is governed by the rule of law.

Trudeau echoed these comments Wednesday.

"Every single person who comes to Canada -- whether it's regularly or irregularly -- goes through our immigration system, gets the full treatment within our asylum system."

But refugee advocates and lawyers say disallowing asylum seekers who have made refugee claims in other countries from making claims in Canada do just the opposite, as it would strip them of their ability to plead their cases to the Immigration and Refugee Board.

For his part, Conservative Leader Andrew Scheer blames Canada's border woes on Trudeau, based on a tweet he issued in 2017 in which he welcomed refugees to Canada. Given the timing, it appeared to be a response to Trump's changes to the U.S. rules.

But Scheer on Wednesday sidestepped questions about the changes to refugee eligibility proposed by the Liberals, focusing instead on his own party's belief in an immigration system that is "fair, orderly and compassionate."

"We have to have a system that prioritizes those fleeing danger, fleeing civil war and natural disasters and that has to be based on our borders having integrity," he said.