A week after Arlen Specter switched parties with the expectation that he would maintain his Senate seniority, Democratic leader Harry Reid said Wednesday that it would be up to Democrats to decide whether the former Republican could reclaim his standing in the next Congress.

Reid was making it clear to disgruntled members of his caucus that an agreement he forged with Specter would be subject to a vote by Senate Democrats.

“Always Sen. Specter and his chief of staff — we thought — understood that his subcommittees wouldn’t be changed, the chairmen wouldn’t be changed, his overall standing in the Senate would be protected. But the only people who are capable of determining status in a caucus is the caucus,” Reid, the Senate’s majority leader, said Wednesday.

This leaves Specter’s standing less certain than Reid described on April 28 when Specter’s switch was announced. Asked then whether the Pennsylvania senator would maintain his seniority, Reid, D-Nev., responded: “That’s right.”

On Wednesday, Reid said that decision would be “up to the caucus.”

For his part, Specter reiterated that Reid had assured him he would keep his seniority and committee assignments and that any decisions on chairmanships of committees and subcommittees would wait until the 112th Congress.

“I am confident my seniority will be maintained under the arrangement I worked out with Sen. Reid,” Specter said in a statement Wednesday. “Some members of the caucus have raised concerns about my seniority, so the caucus will vote on my seniority at the same time subcommittee chairmanships are confirmed in the 2010 election.”

Late Tuesday, the Senate adopted new organizing resolutions (S Res 130 and S Res 131) that made Specter the least-senior Democrat on the five committees on which he now serves.

Asked whether Specter’s loss of seniority on the five committees was the result of resistance from Senate Democrats, Reid said: “There was nothing to resist. That’s how we organize every Congress.”

Four of Five Gavels

With 29 years in the Senate, Specter has a claim on gavels on four of his five committees including that for the Appropriations subcommittee on Labor, HHS and Education, a prospect that disturbed senior Democrats.

Judiciary Committee Chairman Patrick J. Leahy , D-Vt., earlier had suggested creating a new subcommittee for Specter to head. But Leahy said the resolution, which he said he learned about only Wednesday morning, put Specter behind other Democrats who might want a gavel.

“The resolution puts him at the end of the line, and there are people ahead of him,” Leahy said. “I just heard about the resolution. I don’t know what will happen.”