WASHINGTON, March 29 (Reuters) - Thirteen U.S. House Democratic lawmakers on Monday urged the U.S. Postal Service's governing board to halt implementation of a contract that could be worth $6 billion to build up to 165,000 next-generation delivery vehicles.
   In February, the USPS awarded a contract to Oshkosh Corp to build a mix of gasoline-powered and electric vehicles instead of choosing Workhorse Group Inc to build an all-electric fleet.
   The lawmakers, including Representative Gerald Connolly, who chairs a subcommittee that oversees USPS, Jared Huffman, Tim Ryan, Debbie Dingell and others, also suggested the decision was in defiance of an executive order issued by President Joe Biden to electrify the federal government's vehicle fleet. They urged a delay until a full review is completed and Biden's three nominees to the Postal Board of Governors are seated.

(Reporting by David Shepardson; Editing by Dan Grebler)
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