The day after the federal government said it would go to the Supreme Court to try to shut down Vancouver's safe-injection site, supporters of the facility forced the Prime Minister to delay a photo op at a Chinese cultural centre by chaining the doors.
Dozens of Vancouver police officers descended on the site and cut the chains.
The 150 protesters dispersed after an hour with no arrests. However, the demonstration prompted a fierce exchange between the Prime Minister's spokesman and a New Democratic MP who was observing the protest over whether the MP approved locking Chinese Canadians into the building at a risk to their safety.
Nathan Allen, a spokesman for Insite for Community Safety, promised to dog Mr. Harper's Olympic-oriented appearances "if we know where he is."
A recent ruling from the B.C. Court of Appeal validated the right of Insite to operate. The B.C. government supports Insite, which provides addicts with a safe, clean place to use their drugs.
However, the federal Tories have long been opposed to it, with federal Justice Minister Rob Nicholson this week suggesting the appeal court ruling raises questions about federal-provincial jurisdiction.
Not long before the Prime Minister's scheduled photo op at the centre, which is located few blocks from Insite in Vancouver's Downtown Eastside, the protesters wrapped yellow caution tape around the complex, then chained the doors.
Vancouver police said in a statement that chaining the doors presented safety concerns.
"The Vancouver Police respect the right to protest safely and the right to assemble safely. However, in this case, the protesters infringed upon the rights and safety of others," said the statement.
Mr. Harper, according to his office, eventually did visit the centre for a dress rehearsal of the upcoming Vancouver Chinatown Spring Festival Celebration Parade, which included five artistic demonstrations.
Libby Davies, the Vancouver East MP for the NDP, later traded barbs with Dimitri Soudas, a spokesman for Mr. Harper.
Mr. Soudas criticized Ms. Davies for a Twitter remark describing as the protest as impressive, noting in an e-mail that "veterans, seniors and young children" were trapped inside the centre because Ms. Davies's "welcoming committee" had closed all exits. In a subsequent interview he said, "We had an NDP MP outside cheering them on."
He called on Ms. Davies to work against future protests. "I certainly hope Ms. Davies will call on them to stop such forms of violence on the eve of the Olympic Games," he said.
"As an MP for Vancouver, she should be putting a bright light on Vancouver."
Ms. Davies said she was an observer at the protest, and left before it ended. She noted that police were able to enter and leave the building.
"I was there as I have been at many rallies in support of Insite, and I'll continue to do that because I am outraged the Conservative government is continuing to challenge Insite's operation," she said.
Mr. Harper will visit the B.C. Legislature today to speak about the Olympics.
Federal Liberal Leader Michael Ignatieff has given B.C. legislators a list of questions to ask the Prime Minister, who prorogued Parliament until after the Games.
Mr. Harper will meet privately with B.C. Premier Gordon Campbell and then head back to Vancouver to attend the opening ceremonies tomorrow.
In Ottawa, Mr. Ignatieff said it is "ridiculous" that the Prime Minister will deliver a speech about the Olympics in Victoria.
"He ought to be giving it in this room behind us," he said in front of the Commons. "This is the Parliament of Canada. That's where that speech should be given," he said, adding: "I sure hope he doesn't prorogue the B.C. Legislature."
With a report from Campbell Clark in Ottawa