WASHINGTON — A dispute over the proposed federal courthouse in Santa Ana on Thursday turned into what appears to be the first skirmish of the 1994 California Senate campaign, as Democratic Sen. Dianne Feinstein and Republican Rep. Christopher Cox of Newport Beach tangled over the project's funding.

To Cox's dismay, the Senate Appropriations Committee on Thursday adopted legislation that would provide only half of the $168 million that the Clinton Administration had requested for construction of a new federal courthouse and office complex in downtown Santa Ana.

A longtime champion of the courthouse project, Cox has told financial backers that he intends to seek the Republican nomination to run against Feinstein when she comes up for reelection next year.

The $84-million appropriation for the courthouse was part of a $22.3-billion appropriations bill for Treasury, Postal Service and general government operations in the 1994 fiscal year, which begins Oct. 1.

Feinstein, who sits on the appropriations committee, said that full funding is not needed in 1994 because the General Services Administration will not be ready to proceed with courthouse construction until the following year.

"My view of this is very simple," Feinstein said. "There will be money available when the courthouse is ready to go. The . . . language is in the bill."

But Cox said that with proper attention from the GSA, construction could begin well before September, 1994, if the money was available. The GSA last March awarded a design contract for the courthouse to the Zimmer Gunsul Frasca Partnership, a Newport Beach architecture and design firm.

"The only practical effect of this (Senate committee action) can be to delay until at least Oct. 1, 1994, the commencement of construction," Cox said. "There is no good that can come of it. It does not even save the government money. Arguably, it could waste some."

GSA officials were not available for comment Thursday.

During the appropriations committee meeting Thursday, Feinstein took the unusual step of calling attention to language inserted into the bill at her request that, in effect, promises to pay for the rest of the courthouse in the 1995 fiscal year.

She told Sen. Robert C. Byrd (D-W.Va.), the committee chairman, that the language was needed "to avoid any political issue to be made out of this." She added "that some . . . on the other side (of the Capitol) are already beginning to (suggest) that I am not pushing for this."