WASHINGTON — Senator Craig’s political support eroded by the hour yesterday as fellow Republicans in Congress called for him to resign and party leaders pushed him unceremoniously from senior committee posts.

The White House expressed disappointment, too — and nary a word of support for the 62-year-old lawmaker, who pleaded guilty earlier this month to a charge stemming from an undercover police operation in an airport men’s room.

Mr. Craig “represents the Republican Party,” said Rep. Pete Hoekstra of Michigan, the first in a steadily lengthening list of GOP members of Congress to urge a resignation.

The senator’s spokesman declined comment. “They have a right to express themselves,” Sidney Smith said. He said he had heard no discussion of a possible resignation.

Mr. Craig said Tuesday he had committed no wrongdoing and shouldn’t have pleaded guilty. He said he had only recently retained a lawyer to advise him in the case that threatens to write an ignominious end to a lifetime in public office.

Senators McCain of Arizona and Coleman of Minnesota joined Mr. Hoekstra in urging Mr. Craig to step down, as did Rep. Jeff Miller of Florida — and others who joined them as the day wore on.

Mr. McCain spoke out in an interview with CNN. “My opinion is that when you plead guilty to a crime, you shouldn’t serve. That’s not a moral stand. That’s not a holier-than-thou. It’s just a factual situation.”

Mr. Coleman said in a written statement, “Senator Craig pled guilty to a crime involving conduct unbecoming a senator.”

For a second consecutive day, GOP Senate leaders stepped in, issuing a statement that said Mr. Craig had “agreed to comply with leadership’s request” to temporarily give up his posts on important committees. He has been the top Republican on the Veterans Affairs Committee as well as on subcommittees for two other panels.