Parliamentary maneuvering by opponents of a bill that would require safety inspection of trucks before their resale backfired today and the measure - killed in the House of Delegates yesterday - may be resurrected as a result.

As the opponents of the bill attempted to consign it to oblivion today, a freshman delegate apparently was an unwitting accomplice, giving them the opening they wanted.

The assistant majority leader of the House, Del. B.W. (Mike) Donovan (D-Prince George's), a principal planner of today's moves, finally conceded that efforts to kill the bill had failed badly. He admitted that he should have known better than to try to pull a fast one on his colleagues.

Although the bill was left for dead on the House floor yesterday with the help of the powerful trucking lobby, its opponents wanted a second vote today to nail shut the coffin lid. A bill that is reconsidered and defeated a second time is dead for the legislative session.

Today's motion to reconsider was made, apparently in good faith, by freshman Del. Patrick T. Welsh (D-Baltimore County). Before Welsh could resume his chair, Donovan was on his feet, calling to "move the previous question," a parliamentary action that cuts off debate, in this instance before it could even begin.

The sponsor of the bill, Del. Ida G. Ruben (D-Montomery) jumped up, protesting that she was not prepared for the motions, and asked that reconsideration be put off until next week.

Del! Lucille Maurer(D-Montgomery) objected to "this most discourteous" action by Donovan, and urged defeat of his motion to cut off debate.

Even one of the most vigorous opponents of the measure during yesterday's debate, Del. Craig Knoll (D-Prince George's), joined in the outrage.

Donovan's motion wa s then defeated, 42 to 77. A sebsequent motion by Ruben to postpone further debate and a new vote until next Tuesday, was approved, 61 to 35.

When the House recessed, Welsh, 25, a first-term legislator who upset the Democratic organization in Dundalk to win his seat three years ago, apologized to Ruben.

"They told me they would special order (postpone) it until Tuesday," Welsh stammered. Who were they, he was asked. "Donovan, Heffner and Rush," Welsh answered. "Donovan, Heffner and referred to are George E. Heffner and William Rush, fellow members of the Baltimore County Democratic delegation, and strong opponents of the Ruben proposal.

Welsh then walked to the rear of the chamber and collared Donovan.

"I made a mistake," said Donovan. "I angered the House, and when you do that, they'll turn you around every time," added Donavan, who is serving his 11th session.

Donovan acknowledged that he had asked Heffner to ask Welsh to move for reconsideration with the idea that the renewed deabte and vote would occur next week. Because all three of them had voted with the majority yesterday, any of them could have moved for reconsideration today.

When Welsh moved for reconsideration, "I was afraid they would set it for Friday, when I won't be here, so I jumped up," Donovan said. He said later he was "not trying to use" Welsh.

Welsh, a bit embarraseed and angry at appearing to be the "fall guy" in today's power play, predicted the action may backfire. "I wouldn't be surprised if the bill passes now," he said.

When the bill was rejected Wednesday by a vote of 54 to 68, Del. Edward J. Dabrowski Jr. (D-Baltimore) asked to be excused because he is an employee of the trucking lobby organization, the Maryland Motor Truck Association. Today, Dabrowski voted on both motions and each time, voted with opponents of the bill.