The Supreme Court agreed Friday to decide whether Congress unlawfully delegated too much authority to the president last year by granting him the historic power to veto "line items" in the federal budget.

The highest court's speeded-up review will yield by late June what could be a momentous balance-of-powers ruling. The case will be argued before the justices on April 27.The Republican-led Congress voted in 1996 to provide President Clinton with the unprecedented power of canceling specific items in spending and tax legislation, considered a key to fighting wasteful "pork-barrel" projects.

The president used the line-item veto 82 times last year, but Congress is expected to restore 38 of those items with two-thirds majority votes in both the House and Senate.

If the Supreme Court agrees with a federal trial judge who invalidated the law earlier this month, no such veto overrides would be necessary.

U.S. District Judge Thomas Hogan said the 1996 law wrongly "crosses the line between acceptable delegations of rule-making authority and unauthorized surrender to the president of an inherently legislative function; namely, the authority to permanently shape laws and package legis-la-tion."

"The Constitution . . . dictates that once a bill becomes law, the president's sole duty is to `take care that the laws be faithfully executed,' " Hogan wrote.

In the appeal acted on Friday, Justice Department lawyers argued that Congress did not let the president unlawfully usurp its power.