For about two weeks the thin tension had been there, a growing nervousness underlying the hubbub of everyday state house business. Worried legislators would huddle periodically in the marble corridors, asking each other if the governor had really meant what he said.

What concerned the lawmakers was Acting Gov. Blair Lee's pronouncement that he would veto proposed legislation expanding the so-called "circuit-breaker" property tax relief program -- the pet program of most of the legislative leadership.

If Lee vetoed this legislation, the reasoning went, legislative leaders might relaliate by blocking the governor's own property tax relief measures. Inevitably, then, the precariously patched together package of property tax relief legislation would fall apart, leaving 850,000 angry homeowners with no relief at all -- in an election year.

On Thursday, two weeks after he had made his adamant stand against the proposed circuit-breaker expansion -- now being called the "tax credit" bill --Lee backed off. Explaining that "there has been a sort of shuttle diplomacy going on," between himself and the legislators, he added, "there is a possibility that a general accord will be reached" on tax be reached" on tax relief legislation.

"But it's all a little bit like the Egyptians and the Israelis," he cautioned. "It's not there until it's there."

For the first time since the beginning of the 1978 legislative session, Lee seemed amenable to compromise on the property tax issue, which most legislators regard as the key political issue in Maryland in 1978.

There seemed to be at least two reasons for Lee's backpedaling. One he explained himself, continuing his diplomatic analogy: "You put a position on the table and they react to it and then you move over a little and they react again. . ."

"Finally, you arrive at a sort of synthesis of the whole thing and that's the basis of the whole agreement."

Some of the legislative leaders and their aides, however, said that the other reason for the governor's action had more to do with muscle -- legislative muscle -- than it had to do with diplomacy.

First, it is necessary to understand how the legislators assembled the package of bills they are pushing.

By mid-February, three key leaders --House Ways and Means Committee, Senate President Steny Hoyer and House Speaker John Hanson Briscoe --property tax relief bills and come up with six or seven they felt could be moulded into a politically acceptable package.

Of these, three were crucial.

One was the tax credit legislation, which is geared to provide relief for lower-income homeowners through a formula that ties property taxes in part to household income. This bill would expand to all homeowners the present tax credit program, which is available only to the elderly.

An estimated one in four homeowners in the state would qualify for the new program, which could give them up to $450 in property tax relief, all of which would come out of state funds. This ceiling had originally been set at $900, but it is being changed, partially in response to Lee's objections to the program's cost.

By rejiggering the proposed for the cost of this legislation was brought down from the original $48 million estimate to a more generally palatable $33 million. Then to mollify Lee's basic opposition to the thrust of the program, legislators agreed to add a self-destruct clause that would shut the program down in three years unless the legislature passed brand new owners in areas like Baltimore City and Prince George's County. It is also a House of Delegates idea, nurtured over the years by Cardin. Following political custom, If Cacdin and the House got to contribute part of this vote-getting package, then Lee had to be able to contribute a piece of it too.

So the second key section of the package became Lee's favorite idea a measure that would roll back the inflation allowance, allowing taxes to be levied on only 45 per cent of a home's value, instead of the current 50 percent -- in'effect a potential 10 percent tax reduction.

This is a plan that Lee likely to call "tax relief for everybody" -- but it is also anathema to local governments, that stand to lose $45 million in tax revenues statewide. To make up these revenues, these governments say they might have to raise their tax rates, wiping out any potential tax savings for the homeowners and thus making themselves the villains in the property tax drama.

To placate these subdivisions, particularly Baltimore City, Prince George's and southern St. Mary's County, which will be hit the hardest, it is likely that another small bill providing some aid to local governments will be put in the package. A bill to give $12 million in aid to police forces is being given close consideration.

The last of the three major parts of the package is one almost everyone agrees on: a measure continuing for another year the current 15 percent ceiling on annual assessment increases.

The leaders couldn't put together a package without something from the Senate, so they added a measure proposed by Prince George's Democrat Peter A. Bozick allowing local subdivisions to give their taxpayers further breaks on the inflation allowance.

To pay for all of this, particularly the expensive tax credit program, the legislators decided to scrap the governor's plan to increase the amount of standard income tax deduction state taxpayers could take. The cost of the standard deduction proposal was $38 million; it would nicely offset the revised tax credit cost of $33 million.

Throughout all of the process, there were meetings. Every time a major modification in the package was being considered, every time something was down, Cardin or Hoyer or Briscoe or all three -- along with chief fiscal analyst William Ratchford -- would troop over to the statehouse to see how Lee would react.

At other times, Lee's chief lobbyist Tom Peddicord would take himself over to the legislators' offices, carrying the administration's thoughts over to the workshop where the package was being assembled.

It was just after the legislators had completed the delicate process of putting the proposed package together that Lee made his veto pronouncement, apparently throwing everything into jeopardy.

But the legislative leadership did not really take Lee's threats at face value, even if some of their colleagues did. "I didn't interpret (the veto threat) as absolute," House Speaker Briscoe said. "I think he was playing some sort of waiting game to see if we would persist."

Persist they did. A plan evolved to force the issue by pushing through the tax credit bill as soon as possible, putting it on Lee's desk while the governor's favorite bills were still under legislative control.

Lee, however, was watching the Senate carefully. The tax credit bill is a House proposal, and there was growing opposition to it in the more fiscally conservative Senate.

The leadership couldn't put the tax credit bill on Lee's desk -- and then hold his bills hostage -- if the tax credit bill couldn't get through the balky Senate.

However, the governor apparently underestimated the persuasive ability of Senate President Steny Hoyer. By the middle of last week, Hoyer was able to tell his fellow tax credit proponents that he had the "26 or 27 solid votes" needed to get the circuit-breaker out of the 47-member Senate.

"I think Lee looked at the political realities," House Speaker Briscoe said last week. "While he hasn't changed his mind philosophically on the bill, the political reality is that it is going to pass the House and Senate. . . We all want to avoid a confrontation. . .

"We're trying to reach an accord," Briscoe added. "It's not going to make everybody happy, but the combination of points in the package gives everybody a little something. . . I think we've come a long way."