BRATTLEBORO, Vt. — The owners of the Vermont Yankee nuclear plant will ask a federal judge to block the state’s efforts to close the Vernon reactor when its current license expires in March.

Judge J. Garvan Murtha of the U.S. District Court in Brattleboro begins two days of hearings today on whether he should issue a preliminary injunction to block Vermont from closing the plant while the underlying legal battle plays out.

Vermont Yankee owner Entergy Corp. maintains in court papers that it is likely to prevail when the full case goes to trial. It says it already meets the other legal test of irreparable harm because uncertainty about the plant’s future is causing valuable employees to leave.