About 30 protesters delivered 24,000 pink slips to Republican Sen. Susan Collins’ office in Bangor on Friday and asked her to oppose the U.S.-Colombia free trade agreement awaiting congressional approval.

The Maine Fair Trade Campaign, a coalition of 51 organizations and unions across the state, said the pink slips — pieces of paper given to workers as layoff notices — symbolically represented the 24,000 manufacturing jobs lost in Maine since the passage of the North American Free Trade Agreement in 1994 between the U.S., Canada and Mexico.

The protesters said another free trade agreement would put at risk thousands of other jobs in Maine.

“The problem with free trade is that it is sending our jobs overseas,” Daphne Loring, a Maine Fair Trade Campaign coordinator, said. “People are suffering; the middle class is squeezed. The last thing we should be considering is the extension of the NAFTA to Colombia.”

Collins was the only Maine member of Congress who did not take a position on the issue, either supporting or opposing it, Loring said in a telephone interview.

Jen Burita, Collins’ spokeswoman, said the senator had opposed some trade agreements, such as the Central American Free Trade Agreement, and supported others, such as the Chilean Free Trade Agreement.

“In deciding whether or not to support trade agreements, Senator Collins always evaluates the impact on Maine workers and examines the labor and environmental provisions in each pact,” Burita said.

If approved, the agreement would eliminate tariffs and other trade barriers between the U.S. and Colombia.

Both governments signed the Trade Promotion Agreement in November 2006. The legislative branches of both countries need to approve it before it can be enacted.

The Colombian Congress approved it last year. President Bush sent it to the U.S. Congress last April, but the bill did not get out of committee in either the House or the Senate. As a result the bill will likely die, as Congress is on the verge of adjourning.