WASHINGTON (Reuters) - U.S. senators from both parties this week have criticized the Trump administration’s decision that government agencies do not have to provide information to Democratic lawmakers, saying the step will prevent Congress from carrying out its constitutional duties.  During budget and nomination hearings, senators have pressed current and prospective officials about a Justice Department legal opinion dated May 1. The opinion said information requests to executive agencies from senior Democrats on congressional committees, called ranking members, “do not trigger any obligation to accommodate congressional needs and are not legally enforceable through a subpoena or contempt proceedings.” The opinion, largely unprecedented, says agencies are required to give information to only committee chairs, positions held by members of the majority party in Congress. Currently, Republicans control both chambers of Congress and the White House. Most lawmakers first learned about the guidance in media reports last month. Now, they say agencies under President Donald Trump are becoming less responsive to them, making it harder to check whether the executive branch is correctly carrying out laws, as required by the constitution. Some Republicans also have questioned allowing agencies to ignore requests from Congress. Missouri Senator Claire McCaskill, a Democrat who is ranking member of the governmental affairs committee that looks into waste, fraud and abuse in the federal government, grew enraged on Wednesday when a nominee for the White House’s budget office would not commit to respond, without reservation, to her inquiries.  The nominee for Office of Management and Budget Deputy Director, Russell Vought, said that if he is confirmed for the post his responses to her would be “subject to the discretion of the director and advice of legal counsel.” He added that he was “merely reflecting the administration’s policy.” Calling the legal guidance “hogwash,” McCaskill cast withholding information from her as the administration’s attempt to hide problems and wrongdoing. “Welcome to the Big Leagues, administration. This is what happens, you get oversight,” she said, adding she has had a “few problems” with receiving information but not to the extent of other Democrats. A Republican on the committee, Ohio’s Rob Portman, said that when he headed the budget office under former President George W. Bush, he found dealing with Congress was often frustrating. “But I felt it was my responsibility to provide information,” he said, adding he hoped Vought would do so if confirmed for the job. (This version of the story corrects to show Senator McCaskill is from Missouri, not Michigan) 