WASHINGTON A group of 200 U.S. lawmakers on Wednesday said they have agreed not to intervene in the case workers at UPS go on strike.

The world's biggest package delivery firm and the International Brotherhood of Teamsters have until midnight on July 31 to reach a contract deal covering some 340,000 workers that sort, load and deliver packages in the United States.

"We are hopeful that both sides can negotiate in good faith and reach a consensus agreement," the lawmakers said, adding if no deal is reached they have committed to respect the rights of workers "to withhold their labor and initiate and participate in a strike."

(Reporting by David Shepardson)