WASHINGTON -- Democratic U.S. Senate candidate Robert P. Casey Jr. called for stricter rules governing the contact between elected officials and lobbyists yesterday and accused Sen. Rick Santorum of "questionable ethics" practices during his time in the House and Senate.

During a fund-raising trip that included an event last night with Virginia Gov. Mark Warner, Mr. Casey laid out new ethics guidelines he would push for as a senator because he believes power is going unchecked in Washington.

He criticized Mr. Santorum's involvement in the K Street Project, a longtime effort by top Republicans including former House Majority Leader Tom DeLay to expand Republican influence in Washington by helping boost the presence of conservatives in top lobbying groups.

The Washington Post has reported that Mr. Santorum leads regular meetings with K Street lobbying groups and trade associations to discuss Republican candidates for job openings at their firms -- a practice criticized by Democrats.

Though Mr. Santorum said in an interview last night that nothing about the meetings is untoward, Mr. Casey described Mr. Santorum as "the leader of the K Street Project," and described his involvement as troubling.

"These aren't just casual, periodic chance meetings, it's a regular every other week or so process where, not some backbencher, but a Senate leader and others sit down and talk about hiring," Mr. Casey said. "... That is enormous pressure. And I think it's undue influence."

In the give-and-take environment of Washington, Mr. Casey said: "I think you're going to have what amounts to coercion itself or something very close to that. And I think that's why he should end it."

But Mr. Santorum said yesterday that his regular meetings with the lobbying groups are part of his leadership role as the Senate's third-ranking Republican. He described the meetings as a way to inform influential groups who can filter the Republican message out to clients to help achieve Republicans' goals.

While job candidates are discussed, Mr. Santorum said, "there is no pressure to put Republicans in those roles, period -- no pressure. ... I absolutely abhor that."

"The K Street project is purely to make sure we have qualified applicants for positions that are in town," Mr. Santorum said. "From my perspective, it's a good government thing."

In his new ethics plan, Mr. Casey said registered lobbyists should be required to report every substantive conversation they have with a lawmaker on the day the conversation occurs by disclosing it on the Internet. Mr. Santorum said he did not see the utility of the same-day disclosure proposal but had no immediate objection to it.

Mr. Casey also said lawmakers should be barred from traveling on corporate jets, as Mr. Santorum and many other lawmakers do on a regular basis. Current rules require them to reimburse the company for the cost of first class ticket, but Mr. Casey said the real cost is much greater and amounts to special treatment.

Mr. Casey held his discussion with reporters yesterday at the restaurant of Jack Abramoff, a lobbyist with ties to Mr. DeLay who is under criminal and congressional investigation. A spokesman for Mr. Santorum showed up at the event and said Mr. Santorum was challenging Mr. Casey to regular debates because the campaign believes he has been evasive about where he stands on the issues.

Mr. Casey's campaign manager said his candidate would be happy to debate Mr. Santorum after he wins the primary.