Sen. John McCain on Monday accused Sen. Patty Murray (D-Wash.) of directing some $20 million in earmarks to a handful of aides-turned-lobbyists.

In a conference call with reporters organized by Murray’s GOP challenger, Dino Rossi, the Arizona Republican stopped short of calling Murray corrupt. But the one-time presidential candidate did accuse Murray of manipulating the appropriations process.

“A number of the earmarks go to former [Murray] staffers who are now lobbyists,” McCain said.

“I think it’s a corrupt practice. I know it’s a corrupt practice. … She engages in that corrupt practice. Now whether she is corrupt I will let other people make judgment,” McCain said.

McCain also accused Murray of using her position as Senate Democratic Conference Secretary and as a member of the Appropriations Committee to force other Members to accept her earmarks, which he dubbed “a remarkable study in incestuous warfare.”

Rossi has urged a short-term moratorium on earmarks to allow time for lawmakers to review how they are used. Even though Rossi has not called for an all-out ban on the practice, McCain still urged voters to support him: “He will join us in the fight against pork barrelers both Democrat and Republican.” Rossi and Murray are locked in a tight battle for the seat.

Rossi’s campaign in recent weeks has tried to make Murray’s relationship with her former aides who are now lobbyists an issue in the race.

Murray campaign spokeswoman Julie Edwards dismissed the attacks; she charged that as a state Senator, Rossi requested and supported earmarks.

“This is typical of the kind of dirty, hypocritical campaign Dino Rossi has ran since the very beginning. As a state senator, he asked for earmarks, received earmarks, bragged about his earmarks and included earmarks in the budget he says he wrote. And he has a long documented history of intertwining his business dealings with individuals who lobbied him in the state senate,” Edwards said in an e-mail.

Edwards also took a shot at McCain, noting that he opposed key contracts for Boeing Co., one of Washington state’s largest employers.

“Now he attacks Patty Murray for fighting for her state and aligns himself with people who are against the needs of Washington state — including individuals who have actively worked to make sure Boeing doesn’t get the tanker contract. This is simply despicable,” she said.