President Bush, in his first major address to Congress and the nation, unveils a budget plan Thursday that clamps down on defense spending while lifting the lid on funding for some domestic programs.

"He'll lay out the specific programs that make up the budget and all of the provisions that he will be proposing," White House spokesman Marlin Fitzwater said of Bush's televised address to a joint session of Congress at 7 p.m. MDT.Bush's budget plan revises the $1.15 trillion spending plan submitted by Ronald Reagan shortly before he left office.

"This is his first chance to react to the Reagan budget by molding it in a Bush-like fashion," said a White House official who added the revised plan redirects funding to education and other areas, such as the environment.

Sources within the education community said it was likely an additional $1 billion would be pumped into education programs, although many of the 25 programs targeted for elimination by Reagan would still be done away with under the revised plan.

Administration sources said Bush would ask for a military spending level of $309.2 billion, or about $6 billion less than the $315 billion authorization Reagan proposed.

Since spending authority includes funds committed for spending in later years, the actual savings for fiscal 1990, which begins Oct. 1, would be only about $2 billion.

The exact changes in the defense budget have been complicated by the controversy over the nomination of John Tower to be defense secretary - a process likely now to be delayed for weeks.

Although Bush may sharply trim Reagan's request for $5.9 billion in research for the "Star Wars" missile defense system, defense officials said no decision had been made on how the military budget will be revised.

Brent Scowcroft, Bush's national security adviser, has said a final decision should include a review of U.S. strategic (nuclear) weapons modernization, including whether to mount 10-warhead MX missiles on rail cars or develop a single-warhead "Midgetman" missile on a truck launcher.

The president also was expected to call for reducing the capital gains tax from the current 28 percent level to 15 percent as a way to promote more long-term investment in the United States.

The budget package was aimed at letting Bush keep his "no new taxes" vow while cutting the deficit to within the $100 billion limit set by law for the 1990 fiscal year.

The deficit was $155 billion in fiscal 1988 and will hit an estimated $161 billion this fiscal year.