Washington (CNN) -- A year after Congress voluntarily agreed to give up earmarks -- pork barrel spending projects critics say cost too much and may have an outsized influence on some lawmakers -- the special-interest provisions have crept slowly back into legislation, two senators warned on Wednesday.
"There is an effort under way to go back to earmarking as usual, as it used to be," said Sen. Patrick Toomey, R-Pennsylvania. "I think that would be a disaster for our country and our congress and we intend to do our very best to prevent that."
Toomey and Sen. Claire McCaskill, D-Missouri, unveiled legislation Wednesday to ban earmarks permanently and allow lawmakers to strike them easily if they somehow make it into bills on the House and Senate floors.
"I was proud that we got a temporary ban on earmarks in place. But it's not enough," McCaskill said. "With politicians on both sides of the aisle creatively trying to get around the ban, and talking openly about ending it, it's time to end earmarks permanently."
As an example of recent earmark creep, the senators pointed with frustration at a defense spending bill in the House earlier this year, which they said lawmakers tried to use to direct funding to specific home state projects.
"It was a massive attempt," McCaskill said. "There was a slush fund created and then members were allowed to offer amendments to use that slush for fund for pet projects. Then they tried to say it was all going to be competitive. Well, you know, if you look at it closely, it just doesn't pass the smell test."
Last year, the Senate easily defeated a two-year moratorium on earmarks. In response to that vote, congressional Republicans vowed to swear them off voluntarily and promised to defeat any measure that contained them.
McCaskill said it would be politically "dangerous" for lawmakers to vote against her bill. However, top Senate aides on both sides of the aisle were reluctant to predict how a vote might turn out.
In addition to banning earmarks, the McCaskill/Toomey bill would create a process by which lawmakers could challenge any provision believed to meet the definition of an earmark, and a two-thirds majority vote would be required to reject the challenge.