Two new polls depict a cliffhanger in the Republican primary for U.S. Senate.

A survey released yesterday by Quinnipiac University showed incumbent Sen. Arlen Specter with a lead of 49 percent to 44 percent among likely GOP voters in next Tuesday's primary.

A separate poll conducted by SurveyUSA for KDKA-TV showed Specter with a lead of 50 percent to 44 percent among voters who indicated that they were certain to cast a ballot.

The Quinnipiac poll was based on telephone interviews with 431 registered Republicans who said they were likely to vote. Its margin of error was plus or minus 4.7 percent. The SurveyUSA poll included 479 responses to an automated phone message. Its margin of error was plus or minus 4.6 percent.

Specter's six-point lead in the SurveyUSA assessment was nearly identical to the margin he enjoyed in the organization's last poll two weeks ago.

The Quinnipiac survey showed significant gains for Toomey, a three-term congressman from the Lehigh Valley. In its last survey, released April 7, Specter had a much larger lead -- 52 percent to 37 percent.

The difference, said Clay F. Richards, assistant director of Quinnipiac's Polling Institute, came from a sharp erosion in Specter's support among conservative Republicans.