A plan under which welfare recipients could be rquired to work for their benefits will be proposed by President Reagan, possibly as soon as Tuesday when he outlines his new round of budget cuts, government sources said.

Although full details are not known, the plan is to apply to the program of Aid to Families with Department Children (AFDC), which pays benefits to about 3.6 million low-income adults and 7 million children.

Under existing law, states are barred from installing "workfare" plans that make recipients work off some or all their benefits at public jobs, but experiments have been allowed in the past. During Reagan's tenure as governor of California, some work requirements were imposed in that state's program.

Sources said that under the new Reagan plan, devised by Robert B. Carleson, who was Reagan's welfare chief in California and now is a White House program planner, states will be given wide flexibility to shape their "workfare" proposals as they wish to suit local conditions.

Sources said it is likely that some states won't require work from women who are the sole adults caring for very young children in welfare families.

The "workfare" provision," which Carleson repeatedly has espoused in the past, is part of a package of AFDC changes Reagan is expected to outline that are aimed at cutting back anticipated federal outlays for AFDC by at least $1 billion below the program's anticipated $8 billion level for fiscal 1982.

Reagan outlined about $500 million in cuts on Feb. 18, but his new proposals may boost that to at least $1 billion and possibly as much as $1.5 billion, sources said.

Under the existing program, each state sets its basic levels, and the federal government reimburses the states for from 50 percent to 78 percent of each state's total outlay. Low-income states get the higher percentages. State outlays in fiscal 1982 are expected to be $7 billion under current law.

Other changes said to be included in Reagan's proposal:

A major reduction in the amount an individual may earn and still remain on welfare. This would be achieved by reducing earnings that may be excluded when calculating a person's income level for purposes of benefits. At present, the costs of work and day-care for the child of a recipient who works are deducted from income.

Reagan reportedly will propose a firm "cap" on the amount that may be deducted, including no more than $50 a month per child for day care. In addition, he is expected to propose reducing other offsets from income.

Tougher rules on how much propoerty, such as a household goods and personal effects, a person may have and still be eligible.

Allowance for states to count the value of food stamps and government housing assistance as income under certain conditions. In general, under existing law, only cash income is counted when calculating benefits.

In the past, workfare proposals have been criticized strongly by welfare leaders and organized labor. Labor spokesman have warned that welfare clients, forced to work off benefits at low or minimum-wage pay, could become a form of "impressed laborers," undercutting normal wage scales in communities.

They also have argued that the costs of supervising workers on welfare, their possibly low productivity and finding suitable tasks they can do could turn workfare into a losing proposition that would cost more than it saved.

But advocates of "workfare" contend that it can help rid the rolls of people who really do not need welfare payments, many of whom would quit if required to work off their benefits, and can provide valuable work experience for genuinely needy people while accomplishing useful tasks for communities