About 150 union activists and fast-food workers rallied at Seattle City Hall Thursday to call on city leaders to enact a $15-an-hour minimum wage.

“We can’t wait for years. The rent is due now,” said Kshama Sawant, the socialist who become the driving force behind the local movement during the campaign that resulted in her surprise victory in a race for Seattle City Council.

Several dozen marchers braved freezing weather to walk from SeaTac, the site of last month’s victory for a $15-an-hour minimum wage for airport and hospitality workers, to Seattle, where activists hope to pass a similar measure in the coming year.

The marchers reached the plaza outside City Hall at dusk after walking all day. Organized by Service Employees International Union (SEIU) Local 775, the protesters carried signs with the goal — $15 — lit from inside.

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They chanted, “What do we want? 15 dollars! When do we want it? Now!”

City Councilmember Mike O’Brien, who has said he supports passing a $15-an-hour minimum-wage ordinance in 2014, told the marchers that their success in SeaTac had made raising the minimum wage an issue not just locally but across the country.

“People who work full time should make enough to support their families,” he said.

The marchers joined fast-food workers rallying in about 100 cities across the country for a living wage. SEIU Local 775 Vice President Sterling Harders noted that fast-food workers held their first rally in late May when a $15-an-hour minimum wage seemed like “a dream.”

“We’ve come incredibly far in a short time,” she told the cheering marchers.

Washington’s current minimum wage is $9.19 an hour.

Lynn Thompson: 206-464-8305 or lthompson@seattletimes.com. On Twitter @lthompsontimes