A new state lottery, which is one of the revenue measures that Prince George's County needs to avert hundreds of layoffs and program cuts, was approved preliminarily by the Maryland Senate today after opponents made a last-ditch effort to kill the measure or dilute it substantially.

Today's action makes final approval of the "lotto" lottery later this week essentially a pro forma matter. The legislation already has passed the House and Gov. Harry Hughes has said he will sign it.

"This is it," said a relieved Sen. Thomas V. Mike Miller (D-Prince George's) of legislation that is expected to give his financially strapped jurisidiction about $12 million.

"There'll be some talking by opponents when it comes up for a final vote, but this was the fight," said Miller, who made an emotional plea on behalf of the proposal.

An opponent, Sen. Raymond E. Beck (R-Carroll), conceded, "It's not on the hit list."

A few hours later, Prince George's senators fought to save a second bill, before the Senate Budget and Taxation Committee, that would be worth another $10 million to the county by increasing the property tax on businesses.

The bill came over from the House of Delegates with an amendment that said any rise in utility rates caused by the tax would be paid by Prince George's rate payers. The Prince George's delegation offered an amendment today that might require neighboring Montgomery County to share part of any increase. Montgomery County agreed to the change, but the committee voted 7 to 6 to delay action for a day to clarify technical problems.

The Lotto bill creates a new lottery for one year. The new game would employ six digits, with winners drawn weekly. Unlike other Maryland lotteries, from which money goes into the state's general fund, the $38 million proceeds expected from Lotto would be split among the state's 23 counties and the City of Baltimore in direct proportion to the number of lottery tickets sold in each area.

According to a fact sheet distributed today, Prince George's could get the most from Lotto: $11.5 million to be used in fiscal 1984 and 1985. According to County Executive Parris Glendening, this money would allow him to avoid layoffs and some service cutbacks.

Cash-strapped Baltimore would receive $9.6 million. Other jurisdictions, where lotteries are not played as heavily, would receive less: Montgomery, for instance, would get just over $4 million.

For Lotto bettors, who according to boosters are likely to be more middle class than players of the other lotteries, the game could be extremely lucrative as well. The odds of winning are about 250,000 to 1, according to the bill's sponsor, Del. Gerard Devlin (D-Prince George's). But because there may be weeks when no one wins--during which the prize money accumulates--a grand prize could be worth millions of dollars.

But the issue today was not how much people will win but how much the local subdivisions, in particular Prince George's and Baltimore, will gain.

Miller spent most of this morning negotiating with key opponents. At one particularly frantic point, he shooed reporters and onlookers away, saying, "This isn't a public meeting, this is a million-dollar bill we have here."

When the bill came to the floor, Sen. John C. Coolahan (D-Baltimore) offered a series of amendments that Miller and others said could have crippled the bill.

One that passed over the strenuous objections of Baltimore city and Prince George's delegates altered the method for distributing Lotto proceeds to help more affluent counties such as Montgomery and Baltimore.

Although the bill passed, there was no shortage of rhetoric against it and against Prince George's, where TRIM, a voter-approved cap on property tax collections, has been in effect since 1979.

"I'm begging you," said Miller. "It's gotten to the point where a school vice principal is a luxury. We've fired librarians, media specialists. We've fired over 500 teachers. We're not talking about cutting vacant positions. We're talking about firemen, active duty policemen. Every single Prince George's County senator here supported the repeal of TRIM, and we can't get rid of it."