Two key Republican senators are on the verge of proposing that the Consumer Product Safety Commission be abolished and that most of its functions be placed in the Federal Trade Commission, sources said yesterday. f

The plan, being worked out by Sen. Robert Packwood (R.-Ore.), chairman of the Senate Commerce Committee, and Sen. Robert Kasten (R-Wisc.), chairman of the panel's consumer subcommittee, could be proposed to the full committee tomorrow. At that time, the Commerce Committee is expected to consider legislation to revise the CPSC's mission, although Kasten has yet to announce a legislative strategy formally.

Although a significant number of key senators reportedly favor shelving the relatively small agency and its mission -- regulating the safety of tens of thousands of consumer goods -- the Packwood-Kasten proposal would save most of the CPSC's functions.

The Reagan administration has proposed trimming the CPSC's budget next year by 30 percent. James C. Miller III, head the administration's regulatory task force, told Kasten's subcommittee in April that he personally favored making the CPSC part of a Cabinet-level agency.

The FTC also is facing budget cuts under administration plans that would result in the closing of the agency's regional offices. The new plan is likely to grant the FTC more money for its new mission.

Beyond budget-cutting plans and critiques of regulation in general, the administration has not issued proposals for the CPSC. Acting CPSC Chairman Stuart Statler has said that the Reagan budget cuts would cripple the agency, leaving it in a "reactive rather than preventive" state. But Statler, a Republican, also favors consolidating the CPSC's work with that of other federal safety agencies.

Ironically, the current debate about authorizing legislation for the CPSC is similar to the flap over the FTC reauthorization bill last year. At that time, many business groups led an assault on Congress designed to strip the FTC of key powers, a fight that left the agency tattered, if not crippled.

In the CPSC's case a smaller circle of industry groups, ranging from toy makers to manufacturers of formaldehyde, have sharply criticized CPSC efforts to regulate their activities. Those interests essentially have been split between two positions: killing the agency or sharply limiting its mandate.