The spectacle of buttoned-down Canadian diplomats picketing Canada's embassy drew some fascinated stares Friday from tourists and other passersby in the U.S. capital.

About three dozen placard-waving foreign service workers marched in front of the famed Capitol Hill building in an "information picket" aimed at shining the spotlight on stalled negotiations between the federal government and the Professional Association of Foreign Service Officers.

The union has been in a legal strike position since talks with the Treasury Board broke down a month ago. The workers say they are underpaid compared to other public servants with similar qualifications and experience.

The 1,350 union members have already taken part in work-to-rule campaigns that have included refusing to work overtime or to respond to work-related emails after hours.

Though hitting the bricks might go against the discreet, generally well-behaved nature of diplomats, the picket was necessary to highlight significant wage gaps that have been "festering" for years, said union president Tim Edwards.

"We're coming here simply because the U.S. is Canada's most important trading partner and ally, this is our largest mission abroad, and this is one of our largest complements of foreign service officers abroad," Edwards said.

"This was a logical place to raise the profile of our issues abroad, which is equal pay for equal work."

A week ago, foreign service workers in Ottawa held similar pickets at Foreign Affairs headquarters. Edwards said there may be information pickets at other foreign embassies in the weeks to come if negotiations remain at a stalemate.

Diplomats asked to wear sweatpants

At Friday's picket, the diplomats were impeccably dressed — both men and women, including some aides to Ambassador Gary Doer, walked the line in conservative business suits. But that could change: the union is asking diplomats to start a "creative dress" campaign, including wearing sweatpants to work.

"I'd go there," said one picketing worker who asked not to be identified.

Other diplomats in D.C. have been responding to the "creative dress" dictum by wearing lapel buttons to raise awareness about their cause.

"That has the advantage of prompting contacts to ask us what they're about, and then we can explain about the job action," said an embassy employee.

The picketing diplomats received an unintended bit of moral support Friday from a busload of high-school students from Cambridge, Ont., who were exploring the outdoor echo chamber at the embassy.

As the workers made their way down the embassy's front steps to begin their job action, the students simultaneously — and coincidentally — began singing O Canada.