Senior-level civil servants could get pay raises of as much as $24,887.50 next year if the White House and Congress accept new high-level government pay scales proposed yesterday by the blue-ribbon Commission on Executive, Legislative and Judicial Salaries.

The commission known as the Quad Com because it meets every four years to study top U.S. pay rates, made its report to President Carter. He is expected to make some downward modifications and then recommend raises for Congress, new appointees of the Reagan administration and for thousands of top bureaucrats. If the increases went into effect intact, the pay of a Senator or Representative would jump from $60,112.50 to $85,000.

That, in turn, would raise the career-political pay ceiling, and give increases in varying amounts to more than 30,000 persons, the majority in the metro Washington area.

If the Quad Con recommendations were adopted without change, the pay for most members of the Senior Executive Service would jump from $50,112.50 level to a maximum of $75,000. There are about 8,500 SES jobs in government, make up of career and political appointees from the old "supergrade" level of Grades 16, 17 and 18. Persons still in the GS 16, 17 and 18 category -- now similarly frozen at $50,112.50 -- could rise to a maximum salary of almost $58,000 for GS 16s; just over $66,000 for GS 17 personnel and to $70,000 for the handful of GS 18s.

Although President Carter is expected to incorporate some of the Quad Con recommendations in his final budget to Congress, and although the Reagan administration-to-be is eager to be able to pay top dollar to its new personnel, it is unclear what action Congress will take on the proposals.

The final weeks of the lame-duck Congress were spent bickering over -- and finally rejecting -- a more "modest" $10,000 raise for members. The Quad Com proposals would give members of Congress raises of almost $25,000 a year, plus a $10,000 expense account. That may be what it takes to keep Congress from becoming a millionares' club, but it is also political dynamite.

Many top-level U.S. officials have not had a pay raise in four years. Congress has refused to let the career salary ceiling rise above the $50,112.50 mark, even though rank-and-file workers have had pay raises of 7.05 percent, 5.5 percent in 1977 and 1978 and got a 9.1 percent raise last October.

The next step is up to the president, and then Congress. President Carter is expected to return the favor former President Gerald Ford did him four years ago and propose some sort of high-level raises in his final budget. And the incoming Reagan administration, as did the incoming Carter administration four years ago, is expected to go along with some sort of executive-legislative-judicial pay raise.

The problem, as always, will be the political-economic situation. Inflation is high, unemployment is high and John Q. Public, as witness the last election, appears anxious for more economy in government. At a time when major corporations like Chrysler are asking workers to forgo pay raises so they can continue to get paid. Congress could be very sensitive to proposals to give themselves, and top government officials raises that are higher than the gross salaries of most Americans. Other recommendations from the Quad Com include:

Regular annual adjustments (based on what white collar federal wokrers get) each October for members of Congress and top government officials.

A review of top-level federal-executive-judicial salaries every two years, instead of every four years as at present.

Payment of relocation allowances, transportation for family members and household goods, for newly elected members of Congress and top political appointees.

Expense accounts of $10,000 per year for members of Congress.

A study of the more than 40 different federal retirement systems, with suggestions to bring them in line with each other to provide for an exchange of benefits when employes switch from one branch of government to another branch with a different pension program.