WASHINGTON -- The twisting route toward a formal confirmation vote on John R. Bolton as U.S. ambassador to the United Nations took another unexpected turn yesterday when Senate committee action on the nomination was suddenly put off.

The delay appeared to represent the influence of international affairs on this year's congressional elections. Senate officials from both parties said the decision to scrub the vote in the Foreign Relations Committee at the last minute came at the request of Sen. Lincoln D. Chafee, who faces a primary election on Tuesday.

Chafee is considered a moderate Republican and has a conservative primary opponent, Stephen P. Laffey, who says the senator too often breaks with party ranks.

Sen. Richard G. Lugar, R-Ind., the committee chairman, gave no reason for putting off the vote except that he routinely extended the courtesy of such delays when members requested additional time for considering important issues. He did note that in this instance it had been "a Republican request."

Bolton became the U.N. ambassador under a recess appointment by President Bush, bypassing the Senate after Democrats blocked a floor vote on the nomination last year. At the time, Republicans were six votes short of the number required to break a filibuster. The recess appointment expires when this Congress does, in January.

As Bolton has passed through a second nomination process this year, he has been criticized by Democrats, who contend that he has been ineffective at the United Nations and who accuse him of bullying an intelligence analyst and of abusing his authority by seeking names of Americans whose conversations were captured in eavesdropping operations.

Republicans have countered that Bolton has carried out the Bush administration's foreign-policy goals with discipline and energy at the United Nations. That positive assessment was cited in July by Sen. George V. Voinovich, R-Ohio, who withdrew his previous objection and endorsed Bolton.

That switch was thought to have created a fresh dynamic to clear the way for a vote. Even late Wednesday, Senate officials predicted that the nomination would be approved in committee yesterday, along party lines, and sent to the Senate floor.

Although Chafee gave no indication before the meeting of how he planned to vote, he used a July hearing with Bolton to press for a fuller description of the Bush administration's efforts to bring about Middle East peace.

Given the solid block of Democratic opposition to Bolton, the defection of even a single Republican would prevent the committee from sending the nomination to the Senate floor with the panel's endorsement. The nomination could still be sent to the floor without a recommendation.

Last year, Chafee voiced criticism of Bolton but supported his nomination. Asked what had changed in the interim, the senator's spokesman Stephen Hourahan said "several issues in the Middle East," including "the war in Lebanon" and "new settlements in the West Bank within the last week."

"Senator Chafee said he still had questions that were not answered," Hourahan said.

Chafee's office made public a letter he sent Secretary of State Condoleezza Rice later in the day, outlining his "serious questions about this Administration's policies in the Middle East," not Bolton's qualifications and attributes.

As an example, the letter said: "I have been a long-time critic of the disparity between the rhetoric and the actions of the administration on the subject of the Israeli-Palestinian peace process."

He said phase one of the road map the Bush administration laid out for this peace "states clearly that Israel will freeze all settlement activity. Yet, just this week, it is reported that 690 homes will be built in West Bank settlements of Maale Adumim and Betar Illit."

Of this latest development, Chafee said: "While the official U.S. policy has been against settlement activity, no credible observor could think that the U.S. could not do more to stop these new actions," he said.

And, "now I fear that even the rhetoric is going to stop."

His question for Rice: "Is this expansion of settlement activity a signal that holding both sides to their commitments under the road map is no longer official U.S. policy? It is my hope that answers will be forthcoming about our policy toward the Israeli-Palestinian conflict" so the committee "can reconvene to debate Ambassador Bolton's nomination."

When asked what specifically Chafee expected from Bolton, Hourahan said: "As ambassador to the United Nations, there is clearly a bully pulpit."

Meanwhile, Laffey yesterday issued a statement that said, "Once again, Senator Chafee has demonstrated how indecisive he is on the critical issues."

Laffey's statement went on to say that "over the past year, John Bolton has demonstrated that he is a capable and effective representative of America's interests in the United Nations. . . . Even previous critics of Ambassador Bolton have admitted that the ambassador has proven himself over the past year as an effective leader and defender of U.S. interests."

With Journal staff reports from Katherine Gregg and reports from The New York Times.