In a surprise move, Senate Budget Committee chairman Pete V. Domenici (R) of New Mexico offered an alternative budget that would freeze domestic spending, trim the defense budget, and boost taxes by $125 billion over three years.
The alternative plan would reduce the 1983 deficit from an estimated $182 billion to $89 billion.
''Such a decline in projected deficits would have an unprecented impact on the nation's economy,'' he said.
Mr. Domenici said by freezing domestic spending levels for a year he would save $228 billion through 1985. His $125 billion in extra taxes is more than what President Reagan offered to accept during recent budget negotiations.
Included in the alternative plan is a one-year freeze in social security and other federal benefits. Mr. Domenici said a one-year freeze ''would practically assure the solvency of the fund.''
The plan does not have White House endorsement. Mr. Domenici said he outlined his proposals to the President and other Republican leaders, and although little support was expressed, ''No one said, 'Don't present it, senator.' ''
Several Republicans praised the proposal but said they had reservations about it.