Dozens of members of the International Longshore and Warehouse Union Canada rallied in Vancouver, Saturday, protesting what they call "intrusive" powers granted to United States border security officials.

Workers said they are concerned about Bill C-23, which grants U.S. customs and border officials the right to detain Canadians in pre-clearance centres at Canadian airports, cruise ship terminals and other points of departure.

They also say the new law will deny Canadian workers jobs.

"Bill C-23 is draconian legislation that actually gives U.S. Homeland Security officers the power to deny Canadian workers their jobs – in our own country," said ILWU Canada President Rob Ashton.

Efficient flow of goods and people

Bill C-23, the Preclearance Act, has received Royal Assent. This will increase the efficiency and security of the Canada-US border – further strengthening our close relationship. <a href="https://twitter.com/hashtag/cdnpoli?src=hash&ref_src=twsrc%5Etfw">#cdnpoli</a> <a href="https://twitter.com/hashtag/CanUS?src=hash&ref_src=twsrc%5Etfw">#CanUS</a> —@cafreeland

The bill, also known as the Preclearance Act, was introduced by Public Safety Minister Ralph Goodale in June last year, received royal assent on Dec. 14, and will soon become law.

Preclearing customs means Canadian travellers don't have to pass through customs in the U.S., as they've already been approved before leaving Canada.

It replaces and expands powers under the Air Transport Preclearance Agreement signed between the two countries in 2001 and does not allow U.S. officials to arrest Canadians, though individuals can be held or detained.

Several Canadian airports, including in in Montreal, Toronto, Winnipeg, Calgary and Vancouver, permit Canadian travellers to clear US Customs and Border Protection procedures before they board US-bound flights.

Proponents have argued the bill will increase the efficiency of flow of people and goods across the border, but others say it puts Canadian workers and residents at risk.

Fear of discrimination

Bill C-23 was introduced in parliament in June last year by Public Safety Minister Ralph Goodale.

​In Vancouver, protesters — including the president of the British Columbia Civil Liberties Association — said they've been trying to convince the federal Liberals of the law's dangerous precedent for years.

Josh Patterson with the BCCLA said the legislation has implications for all citizens, not just workers in the transportation industry.

He said he's worried U.S. officials would be able to strip search Canadians in pre-clearance centres.

"It's such an intrusive power … This bill has taken that power and given it to the agents of a foreign state, not accountable to us as citizens, not accountable to our own government," Patterson told the crowd at Canada Place.

With files from Deborah Goble