President Reagan, in one of his most partisan radio addresses in months, Saturday accused the Democratic majority in Congress of being budget profligates who seek to elect a "tax-and-spend" president.

And Reagan took credit for the fact that the deficit for the fiscal 1989 federal budget is projected to be below $146 billion. If the deficit exceeded that figure, the Gramm-Rudman balanced budget act requires automatic across-the-board cuts."Left to its own devices, Congress would not have done this," Reagan said.

The Office of Management and Budget informed Congress on Friday that its final projection of the fiscal 1989 federal deficit was just under the $146 billion Gramm-Rudman target. If the projection had exceeded that figure, defense and domestic spending would have been cut by at least $10 billion.

Instead of praising the bipartisan agreement that paved the way for the accord, Reagan offered a back-handed slap at the outgoing, Democratic-run Congress and Democratic presidential candidate Michael Dukakis.

"I'm sorry to say that the Congress' liberal leadership has one answer to everything - and that's raise your taxes. And if they stay in control of the Congress, they may just find a way to raise them," Reagan warned.

Without mentioning either presidential candidate by name, Reagan touted Vice President George Bush's anti-tax stand.

"Why should we have a president who says, `no more taxes' and Congress have a liberal leadership that wants to tax and spend? . . . If we don't want a tax-and-spend liberal in the White House, shouldn't we give the president a Congress that will work with him?" Reagan said.

He did note that Congress had passed all its spending bills on time this year, instead of bundling them into a huge, emergency piece of legislation.

"Congress heard my warning that if that happened again, I'd use my veto pen . . . ," Reagan said. "So we stopped Congress from saying once more `the dog ate my homework' when its budget assignment was due."

In the Democratic response, Rep. Dennis Eckart, D-Ohio, sharply attacked Bush, the GOP presidential nominee.

"George Bush has been a silent partner, riddled with corruption, corruption that has reached into the President's Cabinet, to the Pentagon, from defense contractors to Wall Street. And yet, it was a Democratic Congress this week that spoke of the shared vision with the American people and Mike Dukakis in passing a tough ethics bill that covered ourselves and those who tried to profit from their connections," Eckart said.

Even a cut of $10 billion would make only a small dent in the overall $1.1 trillion federal deficit. Leaders of both parties have sought to avoid triggering the mandatory cuts of the Gramm-Rudman bill, which could offend many interest groups.

"Lots of people were disposed to avoid that," said Sen. Lawton Chiles, D-Fla., chairman of the Senate Budget Committee.

OMB's final projection for the 1989 fiscal year deficit is just under $145.5 billion. The fiscal year began Oct. 1.

If there had been $545 million more in federal spending, the Gramm-Rudman deficit reduction law would have required government expenditures to be cut by whatever amount would have reduced the deficit to $136 billion.

Because of delays in completing anti-drug legislation and other bills, Congress will continue working next week, rather than adjourning for the year Friday as planned.

That means that Congress could pass additional spending bills for fiscal 1989 that would add to the deficit. But under the Gramm-Rudman law, spending enacted after Oct. 15 - which is two weeks into the fiscal year - is not calculated, and there are no legal consequences to adding to the deficit after that date.

However, there would be political consequences.

OMB Director James C. Miller III - who left office Saturday - wrote in his resignation letter that he was urging Reagan to veto any spending measure that would push the deficit beyond $146 billion, even though it would no longer set off automatic cuts.