A U.S. government watchdog on Monday said the Environmental Protection Agency violated the law when it approved a $43,000 soundproof privacy booth for use by the agency's embattled administrator, Scott Pruitt.The Government Accountability Office said EPA failed to comply with a law prohibiting a government agency from spending more than $5,000 in federal funds to furnish or redecorate an office of a presidential appointee such as Pruitt without first notifying congressional appropriations committees.The GAO conclusion that the size of the expenditure for the soundproof booth was illegal is the latest Washington brouhaha over Pruitt's spending practices.Previously, critics say that Pruitt has overspent on first-class air travel and hotel rooms on his business trips and ordered costly extra security because of verbal attacks against him by critics of his environmental policies when they have spotted him in public.Pruitt is one of President Donald Trump's most controversial appointments and has done what he said he would when Trump named him to oversee the country's environmental regulations — dismantle many of the restrictive policies on the environmental practices of businesses imposed by the administration of former President Barack Obama.As news of Pruitt's EPA spending practices has surfaced in recent weeks, some Democratic lawmakers have called for Trump to fire him, an action reportedly echoed behind the scenes by White House chief of staff John Kelly who also called for his dismissal. Other Trump appointees have also been ousted because of spending abuses.But Trump on several occasions gave Pruitt a vote of confidence, saying earlier this month, "I think he’s done a fantastic job. I think he’s done an incredible job. He’s been very courageous. It hasn’t been easy, but I think he’s done a fantastic job.”EPA justified the $43,238 expenditure for the soundproof booth, saying Pruitt needed space where he could use a "classified telephone" so he could have private conversations about agency business."A classified phone cannot simply be put on an office desk or in a conference room," EPA said.EPA said the bill for the soundproof booth, built in a former storage closet in Pruitt's office, included more than $24,000 for the booth itself and its assembly, $8,000 to remove closed circuit television equipment, $3,300 to drop the ceiling around the booth and another $3,300 for painting.GAO said EPA should notify Congress it violated the law, but it was not clear whether the booth would have to be removed.