BOSTON, SEPT. 7 -- Trailing in the final days before the Democratic gubernatorial primary, Massachusetts Lt. Gov. Evelyn Murphy seized on the absence of the state's governor today and issued a pair of executive orders demanding immediate cuts in state spending.

In a strategem mixing elements of comic opera and political hardball, Murphy waited for Gov. Michael S. Dukakis (D) to depart on a trade mission to West Germany, then grabbed a constitutional opening to show herself as a leader, if only briefly.

Members of the lame-duck Dukakis administration, most of whom are openly hostile to Murphy, denounced her move and appeared ready to resist her actions as temporary chief executive. Dukakis, who left Thursday, could rescind any steps taken by Murphy when he returns next week.

"I'm not going to do anything silly," Murphy insisted at a packed Statehouse news conference, denying reports that she had plans to fire Dukakis's top finance official or cabinet members who defy her orders. "I recognize the limits of my authority." Under the state constitution, the lieutenant governor has almost no real power.

Murphy, who won her spot on the ticket in a primary, has never had the confidence of Dukakis and his inner circle. Nevertheless, she remained outwardly loyal through Dukakis's 1988 campaign for president, when he was frequently out of the state, and stood by while the state deficit worsened in the past two years. Murphy's early lead has evaporated in the three-way primary to select the Democratic gubernatorial nominee. Her rivals in the Sept. 18 primary -- former state attorney general Francis X. Bellotti and John H. Silber, the on-leave president of Boston University -- ridiculed Murphy's action.

Early this week, Dukakis learned of Murphy's plan to exploit his absence and canceled his planned trip. After being described as a "hostage" to Murphy's designs and the target of a "palace revolt," Dukakis changed his mind and left the country, but not before denouncing Murphy's plans and taking steps to retain his administration's loyalty.

At a news conference today, Murphy lashed back. She chided Dukakis and his top lieutenants for their "ridiculous, mean-spirited behavior" and accused them of "lying" when they warned that her actions could worsen the state's credit rating.

After months of chronic deficits, sagging tax collections and signs of a new deficit in its $13 billion budget, Massachusetts has the nation's lowest bond rating. The state took another blow today when it was announced that unemployment rose sharply last month to 6.7 percent.

Those conditions, Murphy said, "compelled" her to act. She ordered each cabinet secretary to prepare a monthly report on spending, demanded deep cuts in the top levels of the bureaucracy and called for the immediate sale of surplus state property. In all, she said, her steps could save up to $150 million a year.

Adviser Edward Reilly said Murphy was acting responsibly and showing leadership. He denied she was "swinging for the fences" in the last inning of a campaign.

But most reaction was negative. Critics called her actions a "pathetic gag" and a stunt that could backfire on the entire Democratic ticket by adding to a perception of disarray on Beacon Hill.

Thomas Kiley, a Boston-based political consultant who has worked for Dukakis in the past, was blunt. "She's an idiot. This really confirms it," he said. "It's very damaging to the Democratic Party. . . . It just contributes to the circus-like atmosphere."