Rep. Ed Markey (D-Mass.) is demanding answers from a coal industry group as he continues his probe into a series of forged letters urging Democrats to oppose climate change legislation.Markey, chairman of the Energy Independence and Global Warming Committee, on Wednesday sent a letter to the American Coalition for Clean Coal Electricity asking why the group waited to notify Members of Congress about the forged letters until after the climate change vote.Bonner & Associates, a D.C. lobbying firm that represented the ACCCE, sent at least 12 letters claiming to be from other organizations to three lawmakers: Democratic Reps. Tom Perriello (Va.), Kathy Dahlkemper (Pa.) and Christopher Carney (Pa.). The letters were sent before the June 25 vote on the climate bill; Dahlkemper and Carney both opposed it.According to a press release from Markey, Bonner & Associates told the ACCCE the letters were false a full two days before the vote on the Waxman-Markey clean energy legislation, which ACCCE was attempting to influence, yet none of the Congressional offices were notified about the spurious letters prior to the vote.In his letter to the ACCCE, Markey asks why the group didnt inform affected lawmakers before the upcoming vote. He also asks the ACCCE to describe its relationship with Hawthorn Group, the contractor that hired Bonners firm to conduct grass-roots outreach.The deliberate inaction prior to the House vote and the extended silence after the vote some 40 days after ACCCE knew what had happened raises serious concerns, Markey wrote.The ACCCE has maintained that it left it to Bonner & Associates to inform lawmakers about the matter. The group has until Aug. 13 to respond to Markeys 10 questions.Markey already sent a letter to Bonner & Associates with a dozen questions. The firm has until Aug. 12 to respond.