Lawmakers who say they were double-crossed by a presidential veto are promising to revive legislation that would protect federal workers exposing government fraud and waste. Howls of bipartisan outrage were generated Thursday after congressional sponsors learned that President Reagan won't sign the legislation that his Office of Management and Budget agreed in writing to support. This is hardly the first time that a presidential veto has stirred controversy in Congress, but the reaction was harsher this time because Democrats and Republicans accused the administration of breaking its word. Lawmakers said they relied on letters to sponsors by the deputy director of the Office of Management and Budget, Joseph R. Wright Jr., expressing the administration's backing of the legislation. Sen. Carl Levin, D-Mich., the chief Senate sponsor, said the measure will be introduced again when Congress reconvenes early next year. Sen. Charles Grassley, R-Iowa, echoed the statement. Reagan, who said the version passed by Congress went too far in protecting workers, said he will submit his own bill in January before leaving office. But the 418-0 House vote and unanimous voice vote in the Senate for the congressional version make it unlikely that a Reagan alternative would prevail. Attorney General Dick Thornburgh raised constitutional objections to the bill, which was designed to protect federal ``whistleblowers'' from retaliation by their superiors. The attorney general persuaded Reagan on Wednesday to ``pocket veto'' the legislation _ let it die while Congress is out of session. Thornburgh told reporters Thursday that ``no one is entitled to the protection of unconstitutional legislation.'' He contended that the Justice Department consistently expressed constitutional worries to lawmakers and never signed off on the compromise that passed Congress. Asked if Wright had approval to deal with Congress on the legislation, Thornburgh replied, ``I don't know.'' It was unclear whether OMB and Justice Department officials knew they were pulling in opposite directions, but congressional staffers said they assumed Wright checked with other agencies before writing of the administration's support. OMB spokeswoman Barbara Clay declined to discuss an apparent internal rift, saying only, ``The decision has been made by the president and we support the decision.'' Lawmakers didn't buy Thornburgh's explanation that his department expressed its unhappiness with the bill to Congress during ``any number of exchanges.'' ``It's outrageous conduct and has created a bipartisan explosion, because it violates the basic understanding we need but now no longer have ... that an administration's word is good,'' said Levin. ``There's going to be bipartisan hell to pay.'' Rep. Frank Horton of New York, the chief Republican House sponsor, said he backed the measure ``only when I was assured of the administration's support.'' Horton called Reagan's decision ``a reprehensible act ... orchestrated after adjournment of the Congress to prevent an override.'' Grassley said the administration had ``signed off'' on the bill before Thornburgh stepped in. ``We worked with the administration far too closely for Thornburgh and company to now suggest there are unresolved constitutional questions. ... But then this administration hasn't exactly a sterling record where whistleblowers are concerned.'' Chief House sponsor Patricia Schroeder, D-Colo., said, ``In 1981 President Reagan promised to protect employees who blow the whistle on wrongdoing; now we know how cheap the president's words are.'' Reagan said Wednesday the bill would have allowed employees ``who are not genuine whistleblowers'' to manipulate the process to delay or avoid proper discipline. ``I regret that the Congress did not present me with constitutional and effective legislation to expand the protections and procedural rights afforded to federal employees who report fraud, waste and abuse they discover in federal programs,'' the president said in a statement. ``The interests of both employees and managers should be fully protected,'' the president said. Sponsors said the whistleblower bill was needed because the Office of Special Counsel, established to represent the interests of whistleblowers, was not doing its job. The bill was designed to reverse decisions of courts and the Merit Systems Protection Board, a federal judicial agency, that made it difficult for whistleblowers to win their cases. The bill would have made the Office of Special Counsel an independent agency and would have defined its role clearly as one of protecting whistleblowers. The office now is part of the Merit Systems Protection Board and at times it has acted against whistleblowers who came to the office for help.