WASHINGTON -- A federal judge on Thursday denied Boeing Co.'s request to toss out a government lawsuit that claims the company illegally retaliated against unionized workers by moving some work from Washington state to South Carolina.

The ruling by Administrative Law Judge Clifford Anderson is an early victory for the National Labor Relations Board, which has been widely criticized by Republicans and business groups for bringing the case.

The NLRB alleges that Boeing violated labor laws by opening a new production line for its 787 airplane in South Carolina. The agency claims Boeing opened the new plant to punish Washington state workers for past strikes and wants the company to return the work to Washington.

Boeing denies the charges, saying it opened the South Carolina plant for valid economic reasons. A hearing on the case, which could take months to resolve, began in Seattle on June 14.

While the 21-page ruling comes before any evidence has been presented or testimony heard in the case, Anderson appeared to agree with two of the NLRB's main points. One was that labor law may be violated even though the work was new rather than being taken away from existing workers. The second is that the proposed remedy of moving the new production line back to Washington is not necessarily too harsh.

The 787 is a new plane, and Boeing is just ramping up production now. It is already making them in the Seattle area, where unionized workers will eventually make seven per month. But Boeing also invested $750 million to open a new line in South Carolina, where more than 1,000 non-union workers would build three aircraft per month.

Boeing argues that moving the additional 787 production work to Washington would effectively require shutting down the South Carolina plant. And because the South Carolina plant is new, Boeing has said Washington state workers weren't hurt and no union jobs were lost. In fact, employment in Washington has grown, Boeing said.

But Anderson wrote that labor law could be violated even if a company expands operations to create new work in another state, depriving unionized workers of the additional work.

The lawsuit against Chicago-based Boeing has drawn outrage from Republicans who claim it interferes with the right of company managers to choose where and how to expand business operations. President Barack Obama strongly hinted on Wednesday that Boeing and the Machinists union should be able to settle their differences. Obama said companies should generally have the freedom to relocate, though they must follow the law when doing so.

Boeing said it had not expected to win the motion, and that motions to dismiss are rarely granted before trial.

"The company expects to prevail in federal court on this matter, but not before lengthy and costly legal proceedings within the NLRB and, ultimately, federal court," said spokesman John Dern.

Connie Kelliher, spokeswoman for Machinists District 751 in Seattle, said the ruling shows that Boeing "provided no facts or legal basis as to why the case should be dismissed."